EPA-460/3-73-005
TECHNICAL EVALUATION
OF EMISSION CONTROL
APPROACHES
AND ECONOMICS
OF EMISSION REDUCTION
REQUIREMENTS
FOR VEHICLES
BETWEEN 6,000
AND 14,000 POUNDS GVW
U.S. ENVIRONMENTAL PROTECTION AGENCY
Office of Air and Water Programs
Office of Mobile Source Air Pollution Control
Emission Control Technology Division
Ann Arbor, Michigan 48105
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EPA-460/3-73-005
TECHNICAL EVALUATION
OF EMISSION CONTROL APPROACHES
AND ECONOMICS
OF EMISSION REDUCTION
REQUIREMENTS
FOR VEHICLES BETWEEN
6,000 AND 14,000 POUNDS GVW
Prepared by
L. Bogdan, A. Burke, H. Reif
Calspan Corporation
Buffalo, New York 14221
Contract No. 68-01-0463
EPA Project Officer:
Robert E. Maxwell
Prepared for
U.S. ENVIRONMENTAL PROTECTION AGENCY
Office of Air and Water Programs
Office of Mobile Source Air Pollution Control
Emission Control Technology Division
Ann Arbor, Michigan 48105
November 1973
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This report is issued by the Environmental Protection Agency to report
technical data of interest to a limited number of readers. Copies are
available free of charge to Federal employees, current contractors
and grantees, and nonprofit organizations - as supplies permit - from
the Air Pollution Technical Information Center, Environmental Protec-
tion Agency, Research Triangle Park, North Carolina 27711, or from the
National Technical Information Service, 5285 Port Royal Road, Spring-
field, Virginia 22151.
This report was furnished to the Environmental Protection Agency by Cal-
span Corporation, Buffalo, New York, in fulfillment of Contract No. 68-01-
0463. The contents of this report are reproduced herein as received from
the Calspan Corporation. The opinions, findings, and conclusions expressed
are those of the author and not necessarily those of the Environmental
Protection Agency. Mention of company or product names is not to be con-
sidered as an endorsement by the Environmental Protection Agency.
Publication No. EPA-460/3-73-005
fi
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ABSTRACT
\
An account is presented of a two-part study concerned with the
reduction of emissions from the group of vehicles populating the 6, 000-
14,000 pound GVW range. In the technical evaluation study, state-of-the-art
control technology is utilized to synthesize control system strategies and to
estimate their control effectiveness when applied to this class of vehicles.
The economic analysis study develops the relationships between the different
control strategies and the costs associated with their implementation.
A description is given of a computer program developed to
assess the impact on emissions and to evaluate implementation costs of the
several control strategies. Numerical results are presented.
111
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FOREWORD
This report was prepared by Calspan Corporation, Buffalo,
New York under Environmental Protection Agency (EPA) Contract No.
68-01-0463. The work was administered under the direction of the Office
of Air Programs, Characterization and Control Development Branch,
Division of Emission Control Technology, Mr. Robert E. Maxwell, Project
Officer.
This is the project final technical report which describes and
summarizes the results of studies conducted during the period from
October 1972 through May 1973 and concerned with (A) technical evaluation
of emission control approaches and (B) economics of emission reduction
requirements for vehicles between 6,000 and 14,000 pounds GVW.
Part A effort was performed by the Vehicle Systems Department
with the Part B studies conducted by the Operations Research Department.
Acknowledgement is made of the contributions of D. T.Kunkel who assisted
with the vehicle characterization task and G. M. Niesyty who participated
in the economic analyses and C. Groenewoud who was responsible for
writing the computer program.
A special note of acknowledgement is due to L.H. Lindgren, of
the firm of Rath and Strong, Inc. , for his contributions to lead time estimates
and cost analysis in a consulting capacity.
IV
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ACKNOWLEDGEMENT
The project staff wishes to acknowledge the valuable assistance
rendered by the following organizations in providing information,
documentation and data required in the conduct of this program.
Chrysler Corporation, Detroit, Michigan
Cummins Engine Company, Columbus, Indiana
Ford Motor Company, Dearborn, Michigan
General Motors Corporation, Warren, Michigan
International Harvester Company, Fort Wayne, Indiana
Motor Vehicle Manufacturers Association, Detroit, Michigan
Perkins Engines, Inc., Farmington, Michigan
Recreational Vehicle Institute, Inc.,Des Plaines, Illinois
Wilbur Smith and Associates, Columbia, South Carolina
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TABLE OF CONTENTS
Page No.
EXECUTIVE SUMMARY ES-1
1.0 INTRODUCTION 1-1
2.0 PART A. TECHNICAL ANALYSIS 2-1
2.1 Summary, Conclusions and Recommendations 2-1
2.2 Methodology 2-2
2.3 Vehicle Characterization 2-6
2.3.1 Types and Grouping 2-6
2.3.2 Engines, Drivetrains and GVW Ranges 2-11
2.3.3 Sales 2-20
2.3.4 Usage 2-26
2.4 Representative Vehicle/Engine Combinations 2-37
2.4. 1 Selection 2-37
2.4.2 Emission Controls 2-39
2.4.3 Baseline Emissions 2-39
2.5 Validation of GVW Limits 2-51
2.6 Emission Reduction Potential 2-55
2.6. 1 General Approaches for Reducing
Medium Duty Truck Emissions 2-55
2.6.2 Conventional Gasoline Engines 2-60
2.6.3 Alternative Engines 2-88
2.7 Emission Control Strategies 2-104
2.7.1 Conventional Gasoline Engines 2-105
2.7.2 Alternative Engines 2-109
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Page No.
2.7.3 Computer Simulation of Medium Duty
Emission Control Strategies 2-109
2.7.4 Results of Computer Study 2-114
2.7.5 Control Strategy Evaluation 2-129
3.0 PARTS. ECONOMIC ANALYSIS 3-1
3.1 Introduction and Summary 3-1
3.2 Conclusions 3-3
3.3 Sales Projections 3-5
3.3.1 Introduction 3-5
3.3.2 Projections for 6-10, 000 Ibs. GVW Vehicles 3-5
3.3.3 Sales Projections for 10-14,000 Ibs. GVW
Vehicles 3-15
3.3.4 Recreational Vehicles 3-17
3.3.5 Engines Used in 6-14, 000 Ibs. GVW Vehicles 3-18
3.4 Cost Estimates 3-21
3.4.1 Introduction 3-21
3.4.2 Emission Control Devices 3-21
3.4.3 Incremental Diesel Engine Costs 3-30
3.5 Emission Control System Costs 3-36
3.5.1 Sticker Prices of Emission Control Systems
and Diesel Engines 3-36
3.5.2 Maintenance Costs of Emission Control
Systems and Diesel Engines 3-38
3.5.3 Incremental Fuel Costs of Emission Control
Systems and Diesel Engines 3-42
3.5.4 Total Costs 3-42
3.6 Emission Control System Lead Times 3-47
Vll!
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Page No.
3.7 System Comparisons 3-50
3.7.1 Certification Costs 3-63
3.7.2 Consumer Costs 3-67
4.0 REFERENCES 4-1
IX
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APPENDICES
Appendix A-l Comparison of Specifications for Engines Used in LDV
and HDV Applications
Appendix A-Z A Summary of Exhaust Emissions From Medium Duty
Vehicles, 6,000 - 14, 000 Pounds GVW
Appendix A-3 Evaporative Emissions
Appendix A-4 Identification and Description of Emission Control
Components
Appendix A-5 Supporting Emissions Data for the Evaluation of the
Emission Reduction Factors
Appendix A-6 Supporting Data for the Determination of the Fuel
Penalty Factor
Appendix A-7 Analytical Method for Predicting the Effect of Vehicle
Weight on Emissions
Appendix A-8 Detailed Description of the Medium Duty Truck
Emissions and Cost Program (AMTEC)
Appendix A-9 Graphical Summary of Baseline Emissions Data
vs. Inertia Weight
Appendix B-l
Catalytic Converter Cost and Production Lead
Time
.x
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LIST OF FIGURES
Figure
No. Title Page No.
2..1 Program Information Flow Chart 2-4
2.2 Major Types of Body Styles (6, 000-14, 000 Ib GVW) 2-8
2.3 Relationship Between Tire Diameter, Axle Ratio
and GVW for Medium Duty Vehicles 2-21
2.4 Medium Duty Vehicle Sales 2-27
2.5 Truck Survey in Three Cities-Statistical Summary 2-34
2.7 Regression Lines of HC Emissions on Inertia Weight
for Trucks and Trucks/Motor Homes Combined 2-48
2.8 Regression Line of CO Emissions on Inertia Weight
for Trucks and Trucks/Motor Homes Combined 2-49
2.9 Regression Lines of NO Emissions on Inertia Weight
3C
for Trucks and Trucks/Motor Homes Combined 2-50
2.10 Effect of NO Emissions Level on Fuel Penalty 2-69
x
2.11 Baseline Fuel Economy (MPG) for Medium Duty
Trucks 2-71
2. 12 Effect of EGR on Cylinder Combustion Parameters 2-74
2.13 Comparison of Predicted and Measured Emissions
as a Function of Vehicle Inertia Weight 2-86
2. 14 Conversion Factor Between Engine and Vehicle
Emissions 2-93
2.15 Comparison of Diesel and Gasoline Engine HC
Emissions for Medium Duty Trucks 2-94
2. 16 Comparison of Diesel and Gasoline Engine CO
Emissions for Medium Duty Trucks 2-95
2. 17 Comparison of Diesel and Gasoline Engine NO 2-96
X
Emissions for Medium Duty Trucks
XI
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LIST OF FIGURES (Cont. )
Figure
No. Title Page No.
2. 18 Baseline Diesel Emissions 2-97
2.19 Annual HC Emissions as Functions of Control 2-118
Strategy - Conventional Engines Gasoline
Only - MDV
2.20 Annual CO Emissions as Functions of Control 2-119
Strategy - Conventional Engines Only - MDV
2.21 Annual NO Emissions as Functions of Control 2-120
x
Strategy - Conventional Gasoline Engines Only - MDV
2.22 Annual HC Emissions as Functions of Control Strategy- 2-121
Conventional Engines and Diesels (w/EGR) - MDV
2.23 Annual CO Emissions as Functions of Control 2-122
Strategy - Conventional Engines and Diesels
(w/EGR) - MDV
2.24 Annual NO Emissions as Functions of Control 2-123
x
Strategy - Conventional Engines and Diesel
(w/EGR) - MDV
2.25 Annual Fuel Penalty as a Function of Control 2-125
Strategy - Conventional Gasoline Engines Only - MDV
2.26 Annual Fuel Advantage Using Conventional Engine/ 2-127
Diesel Mix Rather Than Conventional Engines Only-
MDV
2.27 Reference Annual Fuel Consumption for MDV - 2-128
Conventional Engines - No Add-On Control Systems
Xll
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LIST OF FIGURES
Figure No. Title Page No.
3. 1 U.S. Sales of Trucks and Buses 3-6
3.2 U.S. Sales of 6-10, 000 Ibs. GVW Trucks 3-7
3.3 % 6-10, 000 Ibs. GVW Trucks Sales of Total U.S.
Sales of Trucks and Buses 3-9
3.4 Estimated U.S. Sales of 6-10,000 Ibs. GVW Trucks 3-10
3. 5 % U. S. Sales of Pickup Trucks of Total Sales of
6-10,000 Ibs. GVW Trucks 3-12
3.6 Projected Sales of Pickup Trucks 3-13
3.7 Projected Sales of Van/Panel Trucks 3-13
3.8 Projected Sales of Multistop Vans 3-14
3.9 Projected Sales of Chassis and Platform Trucks 3-14
3.10 U.S. Sales of 10-14,000 Ibs. GVW Trucks 3-16
3.11 Catalytic Converter Cost 3-27
3. 12 Catalytic Converter and Thermal Reactor Cost
Estimates 3-28
3. 13 Estimated Costs of Current Spark Ignition Engines 3-31
3. 14 Estimated Costs of Diesel Engines 3-33
3. 15 Incremental Diesel Engine Costs 3-34
3. 16 Estimated System Lead Times 3-48
B. 1 Production Lead Time Schedules for Catalyst and
Substrate Suppliers B-2
B.2 Production Lead Time Schedules for Catalytic
Converter B-3
Xlll
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LIST OF TABLES
Table No. Title Page No.
2.1 Vehicle Grouping 2-9
2.2 Vehicle -Engine -Drivetrain Characterization -
1973 Models 2-12
2.3 Factory Sales of Trucks and Buses by GVW 2-23
2.4 Annual U.S. Domestic Factory Sales 2-24
2.5 Projected 1973 Sales of Medium Duty
Truck Engines 2-26
2.6 Average Daily Truck Usage in 11 Urban Areas 2-30
2.7 Distribution by Body Type and Trip Purpose 2-32
2.7a Group Representative Vehicle -Engine
Combinations, Physical Characterization 2-38
2.7b Group Representative Vehicle - Engine
Combinations, Emission Control Devices 2-40
2.8 Emission Control Devices Presently Used 2-41
2.9 Group Representative Vehicle - Engine
Combinations, Exhaust Emission Levels 2-43
2.10 Emission Control Systems for Conventional
Gasoline I.C. Engines 2-57
2.11 Control System Configurations 2-58
2. 12 Pollution, Cost and Fuel Consumption
Characteristics of Alternative Automotive
Propulsion Systems 2-59
2. 13 Engine Emissions at Low Mileage 2-62
2. 14 Summary of Emission Control System Reduction
Factors 2-68
xiv
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Table No. Title Page No.
2.15 Summary of Emission Control System Fuel
Penalty Factors 2-73
2. 16 Summary of Medium Duty Truck Emission
Control System Effectiveness Data 2-76
2. 17 Summary of Engine Dynamometer Emission
Control System Effectiveness Data 2-77
2.18 Bag Emissions Data from Light Duty and
Medium Duty Vehicles 2-79
2.19 Urban Driving Cycle Characterization Data 2-83
2.20 Road and Engine Horsepowers for Acceleration
and Cruise Modes • 2-84
2.21 Engine Emission Characteristics 2-91
2.22 Summary of Emissions From Diesel Engines 2-98
Equipped with NOX Control Systems
2.23 Emissions Data for Vehicles Using CVCC 2-103
Engines
2.24 Summary of Required Input Information for 2-112
AMTEC Program
2.25 Summary of Computer Runs 2-115
xv
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LIST OF TABLES
Table No. Title Page No.
3. 1 Percent of U. S. Sales of Trucks by Body Types 3-11
3.2 Percent of Sales of 10-14,000 Ibs. GVW Vehicles
by Body Type 3-17
3.3 Sales of Recreational Vehicles 3-18
3.4 Engines in 6-14,000 Ibs. GVW Vehicles Based on
1973 Manufacturers' Sales Projections 3-20
3.5 Emission Control Devices 3-22
3.6 Sticker Prices of Emission Control Systems 3-37
3.7 Sticker Prices of Diesel Engine Systems 3-39
3.8 Incremental Maintenance Costs (50, 000 Mi. ) 3-40
3.9 Incremental Diesel Maintenance Costs (50,000 Mi0 ) 3-41
3.10 Incremental Fuel Costs (50, 000 Mi. ) 3-43
3.11 Diesel Operating Costs (50, 000 Mi. ) 3-44
3.12 Total System Cost (50, 000 Mi. ) 3-45
3.13 Diesel Engine Total System Cost (50, 000 Mi. ) 3-46
3. 14 Emission Control System Comparison V8-350
Engine (50, 000 Mi. ) 3-51
3. 15 Emission Control System Comparison - Diesel 350
CID (50,000 Mi.) 3-52
3. 16 System Comparison V8-350 Engine 3-54
3. 17 Improved Carburetion Effectiveness and Costs -
350 CID Engine (50, 000 Mi. ) 3-55
3. 18 Thermal Reactor Effectiveness and Costs -
350 CID Engine (50, 000 Mi. ) 3-56
3. 19 Catalytic Converter Effectiveness and Costs -
350 CID Engine (50, 000 Mi. ) 3-57
3.20 Diesel Engine Effectiveness and Costs -
350 CID Engine (50, 000 Mi. ) 3-58
3021 Alternative Emission Control Approaches 3-59
3.22 Effectiveness and Costs of Emission Control
Approaches 3-61
3.23 Certification Fleet Requirements 6,000-10,000
Ibs. GVW 3-65
3.24 Certification Fleet Requirements 10,000-14,000
Ibs. GVW 3-66
xvi
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EXECUTIVE SUMMARY
Contents Page No.
1.0 INTRODUCTION ES-1
2.0 PART A. TECHNICAL ANALYSIS ES-3
1. Summary, Conclusions and Recommendations ES-3
2. Supporting Discussion ES-5
a. Methodology ES-5
b. Vehicle Characterization ES-6
c. Baseline Emissions ES-9
d. Weight Limits ES-H
e. Emission Control Approaches ES-13
f. Emission Control Strategies ES-16
3.0 PARTS. ECONOMIC ANALYSIS ES-19
1. Summary and Conclusions ES-19
2. Supporting Discussion ES-21
a. Emission Control Systems and
System Effectiveness ES-21
b. Sales Projections ES-21
c. Costs ES-23
d. Lead Times ES-24
ES-i
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1.0 INTRODUCTION
This program was concerned with a research study devoted to
a technical evaluation of emission control approaches and the economics
of emission reduction requirements for vehicles with a gross vehicle weight
(GVW) between 6,000 and 14,000 pounds. For convenience, this category
of vehicles herein is referred to as medium duty vehicles (MDV).
The objective of the technical analysis was an evaluation of
emission control approaches and reduction levels applicable to the MDV.
A methodology was adopted that included: identification and characterization
of vehicles in the MDV group, selection of representative 1973 model year
vehicle/engine combinations and the determination of their baseline emission
levels, selection of control techniques and alternative engine concepts
providing emission reductions together with engineering estimates of the
levels of these reductions and the identification of lead times and vehicle
performance penalties associated with the different levels of emission
reduction considered feasible. The assumption was made that the extensive
control technology in existence for light duty vehicles (LDV) could be
effectively adapted to the MDV.
A succinct account of the technical analysis study is included
in Section II of this summary.
Relationships among the various reduction levels possible and
their implementation costs for representative MDV vehicle/engine
combinations were developed and analyzed under the economic analysis portion
of the project. Estimated sticker prices for the selected emission control
approaches were estimated together with related maintenance costs and
ES-1
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combined into overall costs which include incremental fuel costs. These
costs are then related to the emission reduction effectiveness of the different
control strategies to determine the cost effectiveness of each.
Section III of this summary is a concise account of the results
of the economic study.
ES-2
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2.0 PART A. TECHNICAL ANALYSIS
1. Summary, Conclusions and Recommendations
Medium duty vehicles are fitted with engine and drivetrain compon-
ents often identical to, or derivatives of, those used in light duty vehicles. The
MDV category is dominated in population by the pickup-type truck whose
dual-purpose function imparts to this weight category, a usage and operating
character not unlike the LDV category. Motor homes, with an appreciable
share of current MDV annual sales, represent a unique exception.
Eight emission control systems are postulated for the MDV
category. These systems are derived from technology developed for the
LDV group and the projected reduction factors, fuel penalties and vehicle
performance effects are estimated with reference to test data from light
duty vehicles. Three categories of control approaches were formulated:
catalytic converter, thermal reactor and fuel control (carbure tion/induction).
These are generic designations and other control devices are included in
the implementation strategies for each.
Using an equivalent 1975 CVS-CH Federal Test Procedure,
baseline emission data are determined from a sample of late model MDV
and show that vehicle weight is the principal factor influencing emissions.
Computer simulation is employed to predict emission reductions
and associated fuel penalties in implementing different control strategies
derived from a combination of control approaches and alternative engines
with lead times estimated for each. This analysis does not incorporate
any effects of durability of control systems on emissions.
ES-3
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Subject to the qualifications noted in the report, the following
conclusions and recommendations are appropriate:
• Exhaust emissions (mass per mile basis) from late
model MDV are principally weight dependent,
increasing with weight.
• A vehicle mix utilizing catalyst equipped
conventional engines and pre-chamber type,
turbocharged diesel engines with EGR provides
the most effective control strategy for HC and
CO emissions.
• The above-cited control strategy also achieves the
best fuel economy.
• A vehicle population comprised solely of conventional
engines equipped with reducing catalysts achieves
the most effective control over NOV emissions.
^-
• It is recommended that emission standards for
medium duty trucks apply to a GVW range bounded
by 6, 000 and 10, 000 Ib. limits.
ES-4
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2. Supporting Discussion
a. Methodology
The technical approach employed in meeting the program
objectives was consistent with explicit procedural details specified by EPA
in the statement of work. Task-type items, requiring continual review and
updating throughout the project, are discussed below.
An initial task required identifying the vehicle types comprising
the 6,000-14,000 Ib. GVW category according to sales, ranges of GVW,
engines, drivetrains, usage and other identifying characteristics. From
these data vehicle groups were formed to aid in validating appropriate GVW
limits for the MDV. For each such group, a representative vehicle/engine /
drivetrain was selected, the current model year emission controls specified
and baseline emissions determined. Emission data, measured according
to an equivalent 1975 Federal Test Procedure, were supplied by EPA. The
group-representative approach proved fruitless as the available emissions
data for MDV did permit discrimination among any of the vehicle/engine /
drivetrain combinations selected. Rather, the principal disciminant factor
found was vehicle test, or inertia, weight.
Using emission control technology from the light duty vehicle
field, likely control systems were formulated for the MDV category with
estimates made for each of reduction factors, vehicle performance penalties
and implementation lead times. A computer program was developed to
calculate annual mass emissions and costs associated with implementing
the individual control strategies in medium duty vehicles.
ES-5
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b. Vehicle Characterization
As indicated above, the planned procedure involved the grouping
of MDV vehicles on the basis of data on usage, sales and vehicle physical
characteristics. Such usage factors as load weight, trips per day, daily
mileage, route followed, etc. were felt to significantly affect emissions.
Usage data of this type were generally very sketchy, out of date and often
completely nonexistent or inapplicable. Consequently, vehicle groups were
formed using judgment and practical considerations based on the limited
data available. The resultant grouping is shown in the table below.
Vehicle Grouping
Group - Body Style or Type
Pickup/Camper Pickup
Camper Special
Van/Passenger Van Van
Passenger Van
Multi-Stop Van Multi-Stop Van
Chassis Cab Chassis
Cowl Chassis
Bare Chassis
Motor Home Chassis Motor Home Chassis
Manufacturers' data on vehicle engines, transmissions and axle
ratios for the different models were collected for the 1973 model year MDV.
A summary of these data, arranged according to the vehicle groupings
selected, appears in Table 2.2 of the report (page 2-12). A number of
significant facts emerge from this compilation. First, all vehicles in the
pickup/camper and van/passenger van groups have GVW specifications
ES-6
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within the range from 6, 000 to 10, 000 Ibs. Second, all models of the other
three groups (except for a single, isolated model) have GVW specifications
either between 6, 000 to 10, 000 Ibs. or 10, 000 Ibs. and above (i. e., only
one model overlaps the 10, 000 Ib. GVW level). Third, the data show that
only one model also overlaps the 6, 000 Ib. GVW level. Therefore the
6, 000 and 10, 000 Ib. GVW levels are distinct demarcation lines among
vehicles with reference to GVW.
The same basic engine families are generally used in the LDV
and MDV groups. Most MDV engines have direct light duty counterparts
and, with few exceptions, are internally identical. Medium duty engines
for the 1973 model year are equipped with fewer add-on emission control
devices and rated at slightly higher horsepower levels than their LDV
counterparts. Intermediate eight-cylinder engines (330-360 CID) are
overwhelmingly popular for the MDV group with the 350 and 360 CID engines
dominant. Six-cylinder engines are a minor factor. It therefore follows
the horsepower-to-weight ratio will be lower for medium duty vehicles so
that the engines will be operated at relatively higher loading than in the LDV.
Vehicle populations and population trends derived from sales
data are important in establishing the impact on total pollutant emissions
attributable to specific groups of vehicles. Using the conventional GVW
groupings of the truck industry, sales data show that the 6, 000-10,000 Ib.
group is by far the most populous if the LDV group (< 6, 000 Ibs. GVW) is
excluded. While this group has exhibited an unbroken trend of increased
sales for the past decade, the sales of the 10,000-14,000 Ib. GVW group
have remained static at a much lower level during most of this period. A
strong sales surge in this latter group, considered substantially attributable
to motor home sales, has occurred since 1970 (Table 2.3, page 2-23 and
ES-7
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Table 2.4, page 2-24). The importance of the recreational vehicles
(campers and motor homes) is highlighted by the estimate that they
accounted for approximately 40% of the MDV sales"" in 1972. On the other
hand, the dominant popularity of the pickup truck is demonstrated by a
51'
share in excess of 55% of annual MDV sales'" over a period of years.
As noted earlier, usage data on MDV are very limited and often
not relevant to specific needs of this program. Specific deficiencies
encountered are tabulated below:
• classification by inappropriate GVW ranges
• use of population samples not typical of the national
distribution of vehicles
• obsolete information based on a nonexistent vehicle
mix
• fragmentary information on daily usage by vehicle
type
Analysis of the more pertinent data shows consensus that all truck types under
10, 000 Ibs. GVW (which includes light duty trucks as well) are urban
oriented and act and operate in traffic much like a typical passenger
automobile. These trucks are found to operate without load for approximately
30% of the time. Pickup-type vehicles and their variants, are used pre-
dominantly for nonwork related purposes. In general, the available usage
data on vehicles in the 6, 000-1 0, 000 Ib. and 1 0, 000-14, 000 Ib. GVW ranges
did not provide any basis for discriminating between the two in establishing
weight limits for the MDV category.
•cln this context, the 6, 000-14, 000 Ibs. GVW range.
ES-8
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c. Baseline Emissions
Emissions data for HC, CO and NOX from over one hundred
late model vehicles with a GVW between 6, 000 and 14, 000 Ibs. were supplied
by EPA. These data originated from three sources, an in-house EPA effort
and two different EPA contractors. The test procedure employed was the
basic 1975 CVS-CH Federal Test Procedure developed for the LDV with the
only variations associated with the determination of vehicle inertia weight
and road load horsepower. Inertia weight, rounded to the nearest 500 Ibs.,
is obtained by the addition to vehicle curb weight of 500-lb. increments
(maximum of 1, 500 Ibs. ) according to a schedule based on payload capacity.
Road load horsepower is given as a linear function of inertia weight, varying
from 17. 7 hp. at 5, 000 Ibs. to 65. 8 hp. at 10, 000 Ibs. These procedural
details do not necessarily represent the test procedures EPA may ultimately
specify for the MDV category.
A review of these emissions data showed that: (a) a number of
older models were included in the sampling (1965-1969), (b) some vehicles
were tested in an "as received" condition while others were tested after the
engine dwell, timing and idle speed were adjusted to specifications, (c) the
bulk of the data was concentrated at an inertia weight of 5, 000-5, 500 Ibs. ,
(d) data at the higher inertia weights (8, 000-10, 000 Ibs. ) were primarily from
motor homes, (e) some vehicles with very low mileage ("green engines")
were sampled, (f) data were included on 1973 California vehicles which were
equipped with EGR systems and (g) the data showed a wide scatter at any
given inertia weight.
The scatter in the emissions data precluded any discrimination
among different vehicle engine combinations. This finding does not imply,
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however, that such differences do not exist. A plot of the data as a function
of inertia weight did show an increase of emissions with weight for each of
the three pollutants.
A series of linear regressions were performed on various
subsets of the data with mass emissions per mile regressed on inertia
weight. Because of the poorly distributed inertia weights, it was necessary
to use a data sample that included all 1970-1973 vehicles, both tuned and
untuned, to extend the range of inertia weights encompassed. California
vehicles and those with green engines were excluded. Results of this
analysis on a sample size of 89 vehicles indicated that the inclusion of
emissions data for only nine motor homes increased the slope of the
regression lines significantly (compared to trucks -only data) for CO and
NO emissions. Consequently, a regression analysis was made for only
J\.
the truck data. Results are given below.
Regression Equations - Trucks Only (76 Points)
= 0.526 Iw + 2.38
= 7-°9 Iw + 19.8
MNOX = i- °2 xw + 1.61
Mj^ = grams /mile of pollutant i
Iw = inertia weight, thousands of Ibs .
Because of the small sample size and narrow inertia weight range available
for motor homes, the emissions data were averaged.
ES-10
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Average Emissions - Motor Homes (9 Points)
HC
gm/mi
7.82
CO
gm/mi
125.71
NOX
gm/mi
13.07
Mean Test
Weight
Ibs.
8,400
Subsequent to completion of work on this project, the Project
Officer supplied emissions data on additional MDV as well as instructions
for broadening the original data base and requested that a regression analysis
be performed for the combined truck and motor home data. The resultant
equations are listed below.
Regression Equations - Trucks and Motor Homes (135 Points)
= 0.555 Iw + 1.94
MCO = H.20 Iw - 8. 19
MNOX = 1-35 Iw - 0.56
These equations were generated after the completion of the project and were
not used in the analysis.
d. Weight Limits
A choice of GVW limits was based on four factors associated
with the vehicles included in the medium duty category; population, physical
characteristics, usage and emissions. The motor home was readily isolated
as a unique member of this group in terms of usage and emissions.
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The selection of 6, 000 Ibs. GVW as a lower limit for the MDV
category is clearly defensible. This GVW level has been shown to be a
natural dividing line at which certain LDV models reach maximum weight
ratings and many MDV models have minimum ratings. Such a line of
demarcation is important in avoiding the necessity of certification of given
vehicle models by two different procedures and according to two different
standards. An alternate possibility, the extension of the GVW range of the
LDV category does not seem reasonable because of the demonstrated dependence
of the MDV emissions on weight. Hence a complex revision of LDV standards
would be implied.
Two possibilities are likely for an upper GVW limit; 10, 000 Ibs.
and 14,000 Ibs. Based solely on GVW ranges of vehicles, the 10,000 Ib.
limit is preferable since only one current year model overlaps this level.
Limited-scope usage data provide no basis for discrimination. On the other
hand, sales data for the 6, 000-10, 000 Ib. GVW group and the similarity of
vehicle characteristics and usage of this group with that of the LDV category
favor the 10, 000 Ib. GVW limit. Also, the choice of the larger weight limit
would bring very few additional trucks under control. Therefore, despite
a lack of preponderant evidence favoring a specific weight limit, the 10, 000 Ib.
GVW figure is recommended as the upper weight limit for the MDV category.
Motor home population is not as stratified by weight as it is for
trucks. Sales and sales projections show a high popularity of the 10, 000-14, 000
Ib. GVW group. Consequently, the limits for motor homes are recommended
to range from 6, 000 to 14, 000 Ibs. GVW.
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e . Emission Control Approaches
Reduction of exhaust emissions from medium duty vehicles may
be realized by (1) modifications of the conventional gasoline engine and/or
exhaust gas after-treatment and (2) the use of alternate, low-emissions
engines.
Emission control systems evaluated for MDV applications were
chosen from those developed and, to a reasonable extent, tested in LDV
applications. These systems offer a wide range of reduction potential and
permit a cost-effective analysis to be made. The systems components
include: engine modifications (EM°), electronic ignition (El), fast choke (FC),
improved carburetion (1C), further improved carburetion (FIC), exhaust
manifold air injection (Al), quick-heat intake (QHI), exhaust gas recirculation
(EGR), oxidizing catalyst (OC), reducing catalyst (RC), air injection ahead of
catalyst (CAI), controlled air injection (AI/CAI), electronic fuel injection and
control (EFIC), three-way catalyst (RC/OC), lean thermal reactor (LTR),
rich termal reactor (RTR) and improved quick heat manifold (IQHI). From
this group of techniques/devices, a total of eight control systems was
identified as shown in the accompanying tabulation. For each system the
emission reductions for HC, CO and NOV have been estimated (Table 2. 14,
X
page 2-68) together with the corresponding fuel penalties (Table 2. 15, page
2-73).
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Emission Control Systems for Conventional
Gasoline Engines
Numbe r System^3-)
EM° (b>
1 EM° + El + FC + AI + EGR
2 EM° + El + 1C + QHI + AI + EGR
3 EM° + El + 1C + QHI + EGR + AI + OC
4 EM° + El + 1C + QHI + EGR + RC + AI/CAI + OC
5 EM° + El + EFIC + EGR + RC /OC
6 EM° + El + 1C + QHI + EGR + LTR
7 EM° + El + FC + EGR + AI + RTR
8 EM° + El + FIG + IQHI + AI + EGR
(a) Components are described in Appendix A-4.
(b) Modifications corresponding to 1972 model year engines,
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Estimates of emission reduction were made primarily from the
experience and data for these systems in light duty applications. . There
are substantial differences between the LDV and MDV classes that affect
the control of emissions. First, the horsepower-to-weight ratio of the
LDV class is relatively high and sensibly independent of vehicle weight. In
the MDV class, this ratio tends to decrease with vehicle weight so that the
engine operates at a higher power loading. Second, the MDV class uses
higher numerical axle ratios resulting in higher engine speeds at a given
vehicle velocity.
Of the alternative engines, only the lightweight diesel and the
prechamber, stratified-charge (CVCC) engine are considered the most
promising at present for the MDV class. The advanced lightweight diesel
engine is visualized as being turbocharged and using a prechamber design.
It is judged to be approximately 25% heavier and larger than comparable
gasoline engines but with much lower baseline emissions and fuel consumption.
This study presumed that the emission and fuel consumption characteristics
of the contemplated lightweight diesel would be the same as those of current
heavy duty diesels of this type.
Estimated baseline emission data for diesel-equipped MDV are
shown in Figure 2. 18 (page 2-97). Since diesel engine emissions data are
available only from engine dynamometer tests, an improvised conversion of
these data to driving cycle (gm/mile) results was necessary. Baseline emission
levels for HC and CO for the lightweight diesel engine appear to be low enough.
that no further control will be necessary. Reduction of NOX levels by about
one half is feasible with only a small fuel penalty with the addition of EGR.
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The Compound Vortex Controlled Combustion (CVCC) engine
recently developed by Honda is a modification of the basic, spark-ignition,
gasoline engine. A variety of the stratified-charge engine, it demonstrates
the low emissions of this type engine. A number of vehicles equipped with
4-cylinder and 8-cylinder CVCC engines have satisfied HC and CO standards
for 1975 without any external control devices. Low levels of NOX were also
achieved without EGR. Because of very limited emissions data, and no
durability data on CVCC engines of a horsepower range useful for MDV
applications, further design and developmental testing of the V-8 engines
is necessary. Continued promising results will make the CVCC engine an
attractive alternative candidate for medium duty vehicles.
f. Emission Control Strategies
From the eight emission control systems (identified in a previous
tabulation) and their associated lead times, three basic control strategies
were selected for analysis of effectiveness to illustrate the range of choices
possible using conventional gasoline engines. These three involve the use
of: (1) improved means of fuel control (systems numbered 2 and 8),
(2) catalytic converters (systems numbered 3, 4 and 5) and thermal reactors
(systems numbered 6 and 7).
In implementing these strategies, lead time considerations
dictate that, in some cases, a combination of two strategies is used. This
is illustrated by the following combinations that were investigated.
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Fuel Control Strategy
Control System No. Model Years Used
(A) 2 1975 onward
(B) 2 1975-1977
8 1978 onward
Thermal Reactor Strategy
2 1975-1976
6 1977 onward
Catalytic Converter Strategy
2 1975-1976
3 1977-1978
5 1979 onward
Fuel control strategy (A) represents a minimum approach to
emission reduction with a mean reduction of approximately 40% in each of
the three principal pollutant from 1972 baseline levels. The catalytic
converter strategy corresponds to the most stringent control schedule and
accomplishes this at a relatively small fuel penalty. Because of its high
fuel penalty, the rich thermal reactor (system no. 7) was not considered
a viable approach and hence was disregarded in the analysis.
A computer program was developed to calculate total annual
emissions and related costs for the medium duty vehicle category during
the time period 1970-1990 for each of the above listed strategies. This
program divided the MDV category into trucks and motor homes, each with
two weight groupings (6, 000-1 0, 000 Ibs . and 1 0, 000-14, 000 Ibs .). Vehicles
of each model year were characterized by engine type and control system
used. For each vehicle/engine/control system, emissions, fuel consumption
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and initial/operating costs were determined. Baseline emissions and fuel
consumption data for each model year vehicle/engine combination were
entered into the program together with factors which described the impact
on each by the individual control strategies. The analysis did not include
a consideration of control system durability. Data on annual vehicle mileage
was also entered according to vehicle type (truck or motor home) as well
as model year. Using sales data (projected and actual) and vehicle scrappage
rage, the vehicle mix on the road in any year was calculated by the program.
Computer runs were made for two different MDV populations.
One which consisted only of conventional gasoline engines and, the other,
which used a mix of conventional and diesel engines. In all cases the
conventional gasoline was a 350 CID V-8 and the diesel was taken to be an
equivalent engine (turbocharged, prechamber, with EGR and with the same
displacement).
With the homogeneous population of conventional engines, the
strategy based on catalytic converters represented the greatest reduction
of all pollutants by a significant margin during the 1980's (Figures 2.19-2.21,
pages 2-118 to 2-120). The corresponding fuel penalty, however, was only
slightly higher than that of the most economical strategy, the fuel control
strategy (B) (Figure 2.25, page 2-125). If diesels are introduced to produce
a heterogeneous engine mix, the catalytic converter strategy still provides
the greatest emissions reductions but now the fuel control strategy (B) is only
slightly less effective (Figures 2.22-2.24, pages 2-121 to 2-123). Some
loss of NOX control, relative to the case of using conventional engines only,
is experienced. On the other hand, a sizable savings in fuel consumption
occurs with diesel engines replacing gasoline engines (Figure 2.26, page
2-127).
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3.0 PART B. ECONOMIC ANALYSIS
1. Summary and Conclusions
The purpose of this study was to develop and analyze the .
relationships between different emission control levels and the cost-of-
ownership of representative 6, 000 - 14, 000 Ibs. GVW vehicle/engine types
equipped with various engine-emission control systems. The costs considered
are the incremental costs incurred from the employment of the emission control
systems. The base line is the 1972 spark ignition engine.
The study encompassed eight emission control systems for use
with existing spark ignition engines and the introduction of a new family of
diesel engines. The former can be classified into three broad categories:
improved carburetion (fuel control), thermal reactors and catalytic converters.
The categories, however, are not mutually exclusive. For example, improved
carburetion features are also used with thermal reactors and catalytic converters,
The diesel engines considered in the study are new or modified designs of
present engines with matched torque converters and automatic transmissions.
Estimated lead times for the spark ignition engine emission control
systems range from 2-5 years. Lead times of 8-10 years would be needed to
reach full production for a new family of diesel engines. This lead time could
be reduced to about 5 years if the objective was to develop one diesel engine
which could have widespread applicability in medium duty vehicles.
The use of improved carburetion for emission control of spark
ignition engines together with the introduction of diesel engines appears as the
best control strategy for medium duty vehicles. This approach would reduce
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annual emissions of HC, CO and NOX by 77, 81 and 64 per cent, respectively
by 1989. This reduction is relative to 1972 base line engines. The 15 year
cost of this approach is $2 billion.
A small further improvement particularly in NOX emission
reductions can be achieved by a mix of diesel and standard gasoline engines
where the latter are equipped with catalytic converter systems. The 15 year
cost of this approach is considerably higher, $3.4 billion.
Diesel engines equipped with EGR result in significant emission
reductions and at the same time provide good fuel economy. Fuel savings
more than offset the higher initial price of such engines.
The improved carburetion and catalytic converter approaches
are the systems of choice in the absence of diesel engines. Implementation
of the former systems will result in the reduction of all pollutants by about
60 per cent by 1989 at a total cost of $3. 7 billion. The latter systems will
reduce emission levels of HC by 79, CO by 72 and NOX by 83 per cent by
1989. The cost incurred, however, is $5.3 billion.
Lean thermal reactor and improved carburetion result in about
equal effectiveness. The former costs more, primarily because of the higher
fuel penalty associated with it.
A detailed comparison of the effectiveness, costs and lead times
of the considered systems is contained in Section 3.7 commencing on page
3-50.
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The cost per mile of vehicle operation attributable to pollution
control systems is generally less than $.01 per mile. The potential impact
of this cost on lease charges is, therefore, not considered significant.
Precise estimates of certification costs cannot be made until
the requirements, engine families and vehicle types are firmly defined. A
crude, preliminary analysis indicates, however, that the potential impact of
certification costs could represent a significant cost, particularly for the
smaller manufacturers.
2. Supporting Discussion
a. Emission Control Systems and System Effectiveness
The emission control systems and their estimated effectiveness
considered in the economic analysis represent inputs from the Part A
Technical Analysis.
b. Sales Projections
Sales projections formed the basis for estimating the total-costs
and reductions in emissions which could be achieved by implementing the
emission control systems.
The vehicles within the 6,000-14,000 Ibs. GVW range fall into
two clearly demarcated weight categories; 6, 000-10, 000 Ibs. and 10, 000-
14, 000 Ibs. In recent years, the former have accounted for 20-24 per cent of
all U.S. sales of trucks and buses, the latter for less than 2 percent.
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Sales projections for vehicles in the 6, 000-10, 000 Ibs. GVW class
were made both in total and as a function of body type: pickup, van/panel,
multistop van and chassis. In 1971, sales of this class of vehicles consisted
of about 500, 000 units. This number is estimated to increase to 650, 000 units
by 1976 and slightly more than 800,000 units by 1980. Pickup trucks represent
between 50 and 60 per cent of the vehicles in this class.
Between 1958 and 1970, annual sales of 1 0, 000-14, 000 Ibs. GVW
vehicles fluctuated between 5,000 and 15,000 units. Sales rose sharply,
thereafter, principally attributable to the popularity of motor homes. The
rate of increase in annual sales between 1970 and 1972 (from 7, 000 to 45, 000)
is not estimated to be sustained. Rather, a more moderate increase is postulated
resulting in annual sales of about 80, 000-100, 000 units by 1980.
Vehicles in the 10-14, 000 Ibs. GVW category consist primarily
of multistop and chassis body types. No pickups or van/panel trucks of
this weight are manufactured.
Sales projections for 6, 000-14, 000 Ibs. GVW vehicles are
presented in Section 3. 3 of the report.
All the body types noted in the previous paragraphs can be and
are used as recreational vehicles. The latter can be divided into two
categories: truck campers and motor homes. According to "Recreational
Vehicles Facts and Trends", the annual sales of truck campers rose from
61,000 units in 1967 to 107,200 in 1971. Comparable sales for motor homes
are 9, 050 and 57, 200.
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c. Costs
The cost measure used for system comparison is the sum of the
initial sticker price of the emission control systems, incremental maintenance
and fuel costs for the specified number of miles. Costs are estimated for three
representative engine families: 16-300 CID, V8-350 CID and V8-454 CID.
Anticipated low and high cost estimates were developed for all systems.
The sticker prices of emission control systems for spark ignition
engines range from about $100 to $300. The first system incorporates
improved carburetion and electronic ignition; the second oxidizing and
reducing converters. The estimated incremental sticker prices of diesel
engines is $400-$800 depending on engine size.
Incremental maintenance costs associated with spark ignition
engines range from about $10 to $300-$400 (based on 50, 000 miles of travel).
The relatively low costs of some systems result from cost savings obtained
through the use of electronic ignition. The high cost systems are those which
require periodic replacement of oxidizing and/or reducing catalytic converters.
The emission control systems of spark ignition engines cause
fuel penalties ranging from 3 to 25 per cent compared to 1972 baseline
engines. In contrast, diesel engines result in significant fuel savings because
of their lower fuel consumption. Anticipated incremental fuel costs for spark
ignition engines range from $90 to $1, 000 based on 50, 000 miles of operation
and a fuel cost of $0.45 per gallon. Fuel cost savings with diesel engines
vary between $650 and $1,400 depending on engine size.
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Total incremental costs (i.e., sticker price + incremental
maintenance + incremental fuel) for spark ignition engines vary between
$350 and $1, 500 based on 50, 000 miles of travel. In comparison, diesel
engines show cost savings of $300-$700. The higher initial sticker prices
of diesels is more than offset by their fuel economy.
Emission control system costs are developed in Section 3.5 of
the report.
d. Lead Times
The estimated lead times are predicated on a sequential
progression of activities culminating in initial production. The emission
control systems considered are presently in various stages of development.
Their current status is considered in determining the lead times.
Improved carburetion together with electronic ignition could be
achieved in 2 years. Systems employing catalytic converters and thermal
reactors require lead times of 4 to 5 years. A major lead time category
here is the construction of new plant facilities and associated tooling. As
noted earlier, achievement of production of a family of diesel engines would
require 8-10 years. The production of one engine with wide applicabilility,
such as a 350 CID diesel engine, given the necessary priority, could be
achieved in about 5 years. Lead time requirements are presented in
Section 3.6 of the report.
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1.0 INTRODUCTION
In the furtherance of improved air quality, it is prudent to
require that motor vehicles utilize available control technology to achieve
a reduction of pollutant emissions to the lowest cost effective levels. This
desirable condition can be achieved by the promulgation of the appropriate
emission standards for new vehicles by the Environmental Protection
Agency.
The present study, concerned with a technical evaluation of
emission control approaches and the economics of emission reduction,
has focussed on that category of vehicles with a gross vehicle weight
(GVW) in the range from 6, 000 to 14,000 Ibs. In the interests of a concise
notation, this category of vehicle is arbitrarily referred to as a medium
duty vehicle (MDV) in this report to differentiate it from the well-established
light duty (LDV) and heavy duty vehicle (HDV) designations.
In assessing the advanced control technology that may be
adapted to the medium duty vehicle to reduce emissions, it is necessary
to identify specific control approaches, determine their developmental
status and estimate their expected effectiveness in the intended application
and service. With the different control approaches attaining production
status at different dates, a variety of control strategies can be postulated
as a function of emission reduction capability, time and attendant costs
which include system initial costs and those related to added maintenance
and operational expenses. From this data base, the objectives of
achieving a reduction of emissions from the MDV by an amount that is
•within the capability of the state-of-the-art technology and is also cost
effective can be achieved. This report describes the studies conducted in
interests of meeting these objectives.
1-1
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Program effort was conducted along two separate technical
disciplines: technical analysis and economic analysis. The objective of the
technical analysis was to conduct a technical evaluation of emission control
approaches and emission reduction levels applicable to medium duty vehicles
in the range from 6, 000 to 14, 000 pounds GVW. This objective was to be
achieved by adopting a methodology that involved: an identification and
characterization of the vehicles comprising this weight group, the selection
of current model year vehicle/engine combinations best representative of
this population together with the establishment of their baseline emission
data, the selection of emission control techniques and advanced engine
concepts for purposes of achieving emission reductions and the estimation
of the reductions thereby feasible, the identification of the levels of emission
control possible as a function of lead time and vehicle performance penalties
and, finally, a discussion of the optimum levels of emission reduction
possible considering performance penalties and lead times. This study
relied on the presumption that further emission reductions could be achieved
in the medium duty category of vehicles by adapting to them the extensive
emission control technology/devices/components that have been developed
for light duty vehicles. A purely analytical evaluation of the efficacy of the
LDV control technology in these vehicles is feasible because of the common-
ality of engines/drivetrains in both the LDV and MDV vehicles.
Results of the technical analysis portion of the program are
presented in Part A of this report.
The economic analysis, Part B of the study, was designed to
develop and analyze the relationships between different emission control
levels and their associated implementation costs for representative vehicle-
engine types which comprise the medium duty class of vehicles.
1-2
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Initially, the sticker prices and maintenance costs of the devices
which comprise the postulated emission control systems are estimated.
These are then combined into system costs. The latter also include the cost
of incremental fuel penalties or savings which are incurred with the systems.
The resultant costs are then compared with system effectiveness for
various emission control strategies. The comparison is made both in terms
of individual vehicle emissions and for aggregations of the total population
of medium duty vehicles.
The results of the study are presented in Part B of this study
which commences with Section 3.0.
1-3
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2.0 PART A: TECHNICAL ANALYSIS
2- 1 Summary, Conclusions and Recommendations
A survey of the literature related to motor vehicles that
populate the 6, 000 to 14, 000 pound GVW range shows that their engine and
drivetrain components are usually identical to, or direct derivatives of,
light duty vehicles. The pickup truck dominates this group in number and,
being a dual-purpose vehicle, gives this class of vehicles a usage and
operating character similar to the light duty vehicle. A singular exception
is the motor home whose current popularity gives it an appreciable share
of the annual sales in this GVW range.
Adapting emission control technology as developed for the
light duty vehicle, a number of emission control systems are postulated as
appropriate for medium duty vehicles. Emission reduction factors, fuel
penalties and effects on vehicle performance are estimated on the basis of
experimental results obtained with light duty vehicles. Three general
categories of emission control approaches are identified: the catalytic
converter, the thermal reactor and the improved fuel control (carburetion/
induction).
Baseline emission data are developed for the medium duty vehicle
group using test data provided from a sample of late model medium duty
vehicles subjected to an equivalent 1975 Federal Test Procedure. These data
show that the dominant factor affecting emissions is the vehicle weight.
Emission control strategies are devised by combining emission
control systems and alternative engines with the projected lead time data
associated with each. A computer simulation procedure is used to predict
the consequences in terms of emission reductions achieved and fuel penalties
2-1
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incurred with the implementation of each of these control strategies.
Durability of emission control systems is not included as a part of this
analysis.
The results of the technical analysis study support the
following conclusions and recommendations (subject to the limitations noted
in the text of this report).
• Exhaust emissions from late model vehicles in the
6, 000-14, 000 Ib. GVW category are primarily a
function of weight.
• The most effective control strategy for HC and CO
emissions visualizes the medium duty vehicle
category using a mix of conventional engines
equipped with catalysts and diesel engines (pre-
chamber, turbocharged, with EGR).
• The best fuel economy is achieved with the control
strategy cited above.
• The most effective control strategy for NO
5C
emissions visualizes the medium duty vehicle
category using conventional engines equipped with
catalysts.
• In setting emission standards for medium duty
trucks, it is recommended that the GVW limits
be set at a minimum of 6, 000 Ibs. and a maximum
of 10, 000 Ibs.
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2. 2 Methodology
The technical approach or methodology followed in the conduct
of this project was generally consistent with the explicit procedural outline
.specified by EPA in the contractural statement of work. A succinct
summary of this outline is provided in the block diagram of Figure 2. 1 where
the individual blocks are serially numbered to indicate a chronological
sequence of execution. In practice, it was found necessary to iterate to
some extent as new or additional information required revision of tentative
judgments or conclusions arrived at in an earlier stage of the project.
The initial task involved the identification of the types of vehicles
comprising the 6, 000 - 14, 000 pound GVW category in terms of population,
sales, usage, ranges of GVW, engines, drivetrains and other unique
characteristics. With these data accumulated, vehicle groups were formulated
for the purpose of validating/recommending the GVW limits for the new
category of medium duty vehicles. For each group thus identified, a
representive vehicle/engine/drivetrain combination was selected to best
reflect all ordinary combinations within that group. For each representative
combination, the current model year emission controls were enumerated
and the associated baseline emission levels determined. These emission
data, which were measured using a test procedure equivalent to the 1975
Federal Test Procedure (FTP) for light duty vehicles, were supplied by
EPA.
Drawing upon the state-of-the-art of emission control technology
as developed for light duty vehicles, a number of likely control system
combinations was selected as potentially applicable to medium duty vehicles.
For each such combination identified, estimates were to be made concerning
emission reduction factors, effects on vehicle performance and lead times
required for implementation.
Emissions data available for medium duty trucks did not permit
discrimination among the group of vehicle/engine/drivetrain combinations
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DESCRIBE EMISSION CONTROLS AND
EMISSION LEVELS FOR CURRENT VEAR
IDENTIFY VEHICLE TYPES
IN 6-1 4 K GVW CLASS
DETERMINE OPTIMUM
GROUPING OF VEHICLES
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selected. The principal discriminant factor was found to be vehicle inertia
(test) weight so that the operation indicated in block number 11 (Figure 2. 1)
was not required. Using lead time data as the determining factor, various
implementation strategies were defined corresponding to the most stringent
schedule of emission reduction as well as lesser intermediate levels. Based
on differing objectives, "best" control approaches to emissions reduction
were considered. In performing this task a computer program was employed
to calculate the estimated annual emissions and costs in applying the various
control strategies to the medium duty class of vehicles.
The succeeding sections of this report discuss in detail the
findings, the results and the conclusions of the studies conducted in the
application of the above methodology in the furtherance of the objectives of
the program.
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2. 3 VEHICLE CHARACTERIZATION
2. 3. 1 Types and Grouping
A study of the manufacturer's truck sales handbooks and the
statistical summaries* published by the Motor Vehicle Manufacturers
Association (MVMA.) shows that the entire population of motor vehicles
comprising the 6, 000 - 14, 000 GVW category may be classified as trucks
designed to transport cargo and persons for personal, business and
recreational purposes. The listing given below characterizes this category
of vehicles according to body style.
Truck Vehicle Types (6,000-14,000 Ibs. GVW)
Pickup . Cab chassis
Passenger Van Cowl chassis
Panel Bare chassis
Van Motor Home chassis
Multi-Stop Van Camper Special
In terms of basic vehicle structures there exist only seven
varieties rather than the ten tabulated above. The pickup and the camper
special are identical except the latter designation indicates the use of a
heavy duty suspension to accommodate a camper unit. This unit is either
built permanently upon the vehicle or else a "slide-in" demountable camper
body is used. For recreational purposes, the pickup may also be equipped
with a portable cover to provide an all-weather protective enclosure over
the bed of the truck. Similarly the van and passenger van share a common
body structure except that in the latter, passenger seats replace the nominal
cargo space and windows are added in the body side panels. Only one model
*Annual issues of "Motor Truck Facts"
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of the entire passenger van line qualifies for classification as a heavy duty
vehicle (see Section 1. 0 for qualifications). This sole exception is the
15-passenger van (Model B-300) made by the Dodge Division of Chrysler
Corporation. The panel truck is not a popular body style and sales in
recent years have decreased to an insignificant level*. Motor homes are
classified into three distinct categories: conventional, van version, and
chopped-van. The conventional type is built upon a bare heavy-duty truck
chassis. The van version converts the nominal interior cargo space of a
van into living quarters whereas the chopped-van type is built directly on
the aft frame section of a van truck retaining the forward section as the
driver compartment. Figure 2.2 illustrates the basic body styles of the
6, 000 - 14, 000 Ib. GVW group of vehicles.
As indicated in Section 2. 2 (Methodology), the initial intent
was to group the vehicles on the basis of information on usage, sales and
vehicle physical characteristics (weight, engine, drivetrain, etc.). Usage,
interpreted to include such factors as weight of load, trips per day, daily
mileage, etc. was considered especially significant in its effect on emissions.
While an attempt was made to pursue this approach early in the program,
a lack of definitive usage data for this category of vehicles (see Section
2. 3. 4 for a discussion of available usage information) necessitated adoption
of a different strategy. Instead, vehicle groups were formed on the basis
of judgment and pragmatic considerations using the limited information
available. The validity of the selections was then tested by checking for
inconsistencies as additional data were obtained or developed. There was
no subsequent need to change this grouping which is tabulated on the following
page.
^Domestic factory sales: 1970 - 777, 1971 - 181; Source: MVMA
2-7
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PICKUP
VAN
MULTI-STOP VAN
CAB CHASSIS
COWL CHASSIS
BARE CHASSIS
NOTE: ONLY TYPES PRESENTLY CLASSIFIED AS HEAVY DUTY ARE CONSIDERED
(REF. CMC 1972 TRUCK MANUAL).
Figure 2.2 MAJOR TYPES OF BODY STYLES (6,000 - 14,000 LB GVW)
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TABLE 2. 1
Vehicle Grouping
Body Style Included
Pickup/Camper . Pickup
Camper Special
Van/Passenger Van Van
Passenger Van
Multi-Stop Van Multi-Step Van
Chassis Cab Chassis
Cowl Chassis
Bare Chassis
Motor Home Chassis Motor Home Chassis
A brief, qualitative explanation for the rationale underlying
these selections is presented below. Specific, quantified information is
contained in the three succeeding sections (2.3.2 - 2.3.4).
Pickup/Camper Group: Sales data show the pickup is an extremely
popular vehicle which has dominated sales of trucks with a GVW of 10, 000
Ibs. and less. Its primary use appears to be about equally divided between
personal and business functions and it tends to be operated in a manner
similar to that of the passenger automobile. With the addition of a camper
unit, the pickup also assumes the role of a recreational vehicle. This
feature , however, does not create a single-purpose vehicle and hence the
camper version is included in the pickup group.
Van/Passenger Van(/Panel) Group: This group essentially consists
of only the forward control van which is principally used in the wholesale and
retail trade with a GVW range that does not exceed 10, 000 Ibs. The panel truck
is included primarily because it needs to be accounted for in the presentation
of sales of medium duty trucks in previous years (Section 2. 3. 3). U. S.
domestic sales data for the 12-month period ending December 31, 1972,
(MVMA FS-20) show that no panel trucks with a GVW over 6, 000 Ibs. were
2-9
-------
produced. The passenger van category, as cited earlier, includes only
one model of one manufacturer.
Multi-Stop Van: Multi-stop, or step vans, comprise a unique
vehicle group characterized by ownership and usage that is entirely com-
mercial. The principal usage patterns are also unique reflecting a
stop-idle-go type of delivery and pick-up service on fixed routes (home
milk delivery, for example) or variable routes (parcel delivery). This
group of vehicles appears to be concentrated in urban areas and especially
the central business districts of large metropolitan areas (New York City
is one identifiable example, Reference 2).
Chassis: Vehicles in the chassis group are manufactured and
sold without bodies. Specialized body builders complete the manufacture
of the vehicle by constructing the body portion in accord with the intended
functional usage. Cab chassis types are generally fitted with a box-style
body while the cowl chassis is usually bodied as a bus. Bare chassis units
are often of the forward-control variety and are converted into multi-stop
van configurations. This group, at its upper GVW end, includes vehicle
types whose GVW limits range well above 16, 000 Ibs. Because of the many
special use vehicles that originate from these general chassis types, a
concise statement concerning usage is not feasible. Broadly stated, the
uses are commercial, industrial and agricultural.
Motor Home Chassis: The motor home chassis is purchased by
specialized manufacturers who complete the construction of the motor home.
As a result of the popularity of this type vehicle, some of the major man-
ufacturers (Ford and GM, for example), contrary to prior practice, are
now producing the entire vehicle themselves. The separate classification
of this group is unequivocal. As a group, they are unique, single-purpose
vehicles probably operated near rated GVW. Their principal usage is for
vacation/week-end trips. Vacation trips may consist of one or two extended
trips (1,000 - 2, 000 miles) while week-end trips, averaging several hundred
2-10
-------
miles each, may be highly variable in number. The motor home is operated
infrequently in urban areas and probably is unused for much of the year.
2. 3. 2 Engines, Drivetrains and GVW Ranges
An important part of vehicle characterization is the identification
of the engines, transmissions and axle ratios that are employed in the
6, 000 - 14, 000 GVW range of trucks. In general, all of these parameters
tend to be loosely correlated with vehicle gross weight, that is, the engine
displacement and numerical axle ratio will usually increase with weight.
All of these factors would also be expected to impact on the emissions of
the vehicle.
Using the manufacturer's truck sales handbooks for 1973, the
following data were gathered for each of the major manufacturers vehicle
models in the 6, 000 - 14, 000 Ib. GVW range: model designation, body
type, axles, GVW, GCW (curb weight), engine (number of cylinders and
CID), type transmission and numerical axle ratio. A summary of this
information is given in Table 2. 2 where the vehicles are arranged by the
groups identified in the previous section.
A number of significant and interesting observations can be
made from this compilation. One relates to the GVW specifications. All
of the vehicles included within the pick up/camper and van/passenger van
groups have GVW ranges totally contained within the range from 6, 000 to
10, 000 Ibs. Also, in the case of the remaining three groups (multi-stop
vans, chassis and motor home chassis) all of the models, with but a single
exception, have GVW ranges either between 6, 000 - 10,000 Ibs. or above
10,000 Ibs. The lone exception is the Chevy/GMC P30/P35 model with a
*
7, 600 to 14, 000 Ib. GVW range. On the other hand, a number of models
are shown with ranges that exceed, or overlap, the 14, 000 Ib. level from
below. Considering the 6, 000 Ib. level from below, one finds that there
are a number of vehicles with a maximum GVW of 6, 000 Ibs. but, again,
# MVMA sales data for the past two years fail to show any sales of GM
vehicles with a GVW rating in the 10, 000-14, 000 Ib. range despite
the availability of this model.
2-11
-------
TABLE 2.2
VEHICLE-ENGINE-DRIVETRAIN CHARACTERIZATION - 1973 MODELS
GROUP 1: PICK UP/CAMPER
t\>
i—>
ts)
Vehicle
Dodge D-200
Dodge D-300
Dodge W-200
Dodge W-300
Ford F-250
Ford F-250
Chevy/GMC
C20/C25
Type Axles GVW
Pickup 4x2 6.2- 9.0
and Camper
Special
Pickup 4x2 6.6-10.0
Pickup 4x4 6. 5-8. 0
Pickup 4x4 8.5-10.0
Pickup 4x2 6. 2-8. 1
Pickup 4x4 6. 5-7. 7
Pickup 4x2 6.4-8.2
GCW Engine
3245-4011 6-225
8-318
8-360
8-400
3795-5240 6-225
8-318
8-360
8-400
3810-4555 6-225
8-318
8-360
8-400
4320-5335 6-225
8-318
8-360
8-400
3520-3940 6-300
8-360
8-390
3965-4385 6-300
8-360
4014-4916 6-250
6-292
8-307
8-350
8-454
HP
110
150
180
200
110
150
180
200
110
150
180
200
110
150
180
200
114
148
161/153
114
148
100
120
130
155
240
Tram
M3
A3
A3
A3
M3
M3
M3
A3
M3
M3
A3
A3
M3
M3
M3
A3
(M3)
(M3)
(A3)
M4
(A3)
(M3)
(M3)
(M3)
(A3)
(A3)
3. Axle
4. 10
4. 10
4. 10
4. 10
4. 56
4.56
4. 10
4. 10
4. 10
4. 10
4. 10
4. 10
4.88
4.88
4.88
4.88
(4.10)
(3.73)
(3.73)
4. 10
4. 10
(4.10)
(4.10)
(4.10)
(4.10)
(3.21)
-------
CROUP 1. (continued)
t\>
i
Vehicle
Chevy/GMC
C30/C35
Chevy/GMC
K20/K25
I-H- 1210
I-H 1310
Type Axles GVW GCW Engine
Pickup 4x2 6.6-10.0 4313 4921 6-250
6-292
4340-5048 8-307
8-350
8-454
Pickup 4x4 6.8-8.2 4313-4438 6-250
6-292
4448-4573 8-307
8-350
Pickup 4x2 6.3-8.2 3510-4050 6-258
8-304
8-345
8-392
4x4 6.3-7.7 3820-4305 6.258
8-304
8-345
8-392
Pickup 4x2 7.0-10-0 3715-4155 6-258
8-304
8-345
8-392
4x4 7.0-10.0 6-258
4375 8-304
8-345
8-392
HP
100
120
130
155
240
100
120
130
155
113
137
144
179
113
137
144
179
113
137
144
179
113
137
144
179
Trans.
(M3)
(M3)
(M3)
(M3)
(A3)
(M3)
(M3)
(M3)
(A3)
(M4).
(M3)
(M3)
(A3)
(M4)
(M3)
(M3)
(M3)
(M5)
(M4)
(M4)
(A3)
(M4)
(M4)
(M4)
(M4)
Axle
(4. 10)
(4.10)
(4.10)
(3.73)
(3.73)
(4.56)
4.56
4.56
(4.10)
4. 10
4. 10
3.73
3.73
4. 10
4. 10
4. 10
4. 10
4.87
4.87
4.30
4.30
4.87
4.87
4.87
4.87
Ford E-300
Camper
Special 4x2
8.3
3655
8-302
139
A3
3. 73
-------
GROUP 2: VAN/PASSENGER VAN
Vehicle
Dodge B-300
Ford E-300
Chevy/GMC
G30/G35
Chevy/GMC
P20/P25
Chevy/GMC
P30/P35
I-H
Type Axles
Pass. Van
Van 4x2
Van 4x2
Van 4x2
Multi-Stop
Van 4x2
Multi-Stop
Van 4x2
Multi-Stop
Chassis 4x2
GVW GCW engine
6.2-7.7 4035-4210
6.2-8.2 3695-3985 6-225
8-318
8-360
6.0-8.3 3845-4015 6-300
8-302
6.2-7.9 3886-4046 6-250
6.2-8.3 4052-4212 8-350
GROUP 3: MULTI-STOP VAN
6.8-8.0 4701-5578 6-250
6-292
4849-5676 8-307
8-350
7.6-14.0 4870-6010 6-250
6-292
5018-6158 8-307
8-350
8-454
10.0-14.0 6-258
8-345
n±~
110
150
180
118
139
100
155
100
120
130
155
100
120
130
155
250
113
144
J. X CL110 *
A3
A3
A3
(M3)
(A3)
(M3)
(A3)
(M3)
(M3)
(M3)
(A3)
M4
A3
M4
(A3)
(A3)
(M4)
(M3)
J-^rt-Xt-
4. 10
4. 10
4. 10
(4.10)
(3.73)
4. 56
(4. 10)
(4.56)
(4. 56)
(4.56)
(4. 56)
(4.56)
(4. 10)
(4.10)
(4.10)
(4.10)
4. 56
4. 87
-------
GROUP 4: CHASSIS
Vehicle
Type
Axles
GVW
HP
Trans.
Axles
Dodge D-200
Dodge D-300
Dodge W-200
Dodge W-300
Dodge MB300
Dodge CB300
(P400)
Ford F-250
Cab
Chassis 4x2 6.2-9.0 3245-4040
and Platform
Cab
Chassis 4x2 6.6-10.0 3795-5240
Platform 4x4 8.5-10.0
Cab
Chassis 4x4 8.5-10.0 4320-5335
and Platform
Cab
Chassis 4x2 8.2-9.0 3714-3826
Bare
Chassis 4x2 13.6-17.4 4025-4080
Cab
Chassis 4x2 6.2-8.1 3520-3940
4x4 6.5-7.7 3965-4385
6-225
8-318
8-360
8-400
6-225
8-318
8-360
8-400
6-225
8-318
8-360
8-400
6-225
8-318
8-360
8-400
8-360
6-225
8-318
8-360
6-300
8-360
8-390
6-300
8-360
110
150
180
200
110
150
180
200
110
150
180
200
110
150
180
200
180
110
150
180
114
148
161/153
114
148
M3
A3
A3
A3
M3
M3
M3
A3
M3
M3
A3
A3
M3
M3
M3
A3
A3
A3
A3
A3
(M3)
(M3)
M4/A3
M4
(M4)
4. 10
4. 10
4. 10
4. 10
4.56
4.56
4. 10
4. 10
4. 10
4. 10
4. 10
4. 10
4.88
4.88
4.88
4.88
4. 10
4. 10
4. 10
4. 10
(4.10)
(3.73)
(3.73)
4. 10
4. 10
-------
GROUP 4: (Continued)
Vehicle Type
Axles
GVW
GCW
HP
Trans.
Axle
Ford F350
Ford P350
Ford P400
Ford P500
Ford F500
Chevy/GMC
C20/C25
Chevy/GMC
C30/C35
Chevy/GMC
K20/K25
Cab
Chassis 4x2
Bare
Chassis 4x2
Bare
Chassis 4x2
Bare
Chasis 4x2
Cab 4x2
Chassis
Cab
Chassis 4x2
Cab
Chassis 4x2
Cab
Chassis , 4x4
6.6-10.0 3740-5010 6-300
8-360
8-390
6.1-8.0 2615-2770 6-300
7.0-10.0 3100 6-300
10.0-15.0 3805-3905 6-300
14.0-19.2 6-300
4960-5090 8-330
6.4-8.2 3619-4392 6-250
6-292
3754-4527 8-307
8-350
8-454
6.6-10.0 3778-4401 6-250
6-292
3905-4528 8-307
8-350
8-454
6.8-8.2 3918 6-250
6-292
4043 8-307
8-350
114
148
161/153
114
114
126
114
137
100
120
130
155
240
100
120
130
155
240
100
120
130
155
(M4)
(M4)
M4/A3
(M3)
(M3)
(M3)
(M4)
(M4)
(M3)
(M3)
(M3)
(A3)
(A3)
(M3)
(M3)
(M3)
(M3)
(A3)
(M3)
(M3)
(M3)
(A3)
(4.56)
(4.10)
(3.73
(4.56)
(4. 56)
(6.2)
(6.2)
(5.83)
(4.10)
(4. 10)
(4.10)
(3.73)
(3.73)
(4.10)
(4.10)
(4.10)
(3.73)
(3.73)
4.56
4. 56
4.56
(4.10)
-------
GROUP 4: (Continued)
Vehicle Type
Axles
GVW
GCW
Engine
HP
N)
I
Trans.
Axle
I-H 1210 Cab
Chassis 4x2
4x4
I-H-1310 Cab
Chassis 4x2
I-H-1310 Cab
Chassis 4x4
I-H -15 10 Cab
Chassis 4x2
Dodge M300/ Motor Home
R300 Chassis 4x2
6.3-8.2 3510-4050 6-258
8-304
8-345
8-392
6.3-7.7 3820-4305 6-258
8-304
8-345
8-392
7.0-10.0 3715-4155 6-258
8-304
8-345
8-392
7.0-10.0 4375 6-258
8-304
8-345
8-392
, 13.8-15.0 4620-4685 6-258
8-304
8-345
8-392
GROUP 5: MOTOR HOME GRASSES
11.0 3575-3820 8-318
8-440
113
137
144
179
113
137
144
179
113
137
144
179
113
137
144
179
113
137
144
179
160
240
(M4)
(M3)
(M3)
(A3)
(M5)
(M4)
(M4)
(A3)
(M5)
(M4)
(M4) .
(A3)
(M4)
(M4)
(M4)
(M4)
(M5)
(M4)
(M4)
(M4)
A3
A3
4. 10
4. 10
3.73
3.73
4.87
4.87
4.30
4.30
4.87
4.87
4.30
4.30
4.87
4.87
4.87
4.87
5. 57
5.57
4.87
4. 87
4.88
4.56
-------
ro
i
oo
GROUP 5: (Continued)
Vehicle Type
I-H
Axles
GVW
GCW
Engine
HP
Motor Home
Chassis 4x2
10.0-14.0
8-392
179
Trans.
A3
Axle
Dodge M400/
R400
Dodge R500
Ford M400
Ford M450
FordMSOO
Chevy/GMC
P30/P35
Motor Home
Chassis 4x2
Motor Home
Chassis 4x2
Motor Home
Chassis 4x2
Motor Home
Chassis 4x2
Motor home
Chassis 4x2
Motor Home
Chassis 4x2
13.0 8-318
13-440
8-440
8.0-10.0 3450-3550 8-360
8-390
11.0 4135-4225 8-360
8-390
12.0-15.0 4135-4225 8-390
7.6-11.8 3229-3348 8-350
8-454
160
240
240
148
153
148
153
153
155
250
A3
A3
A3
A3
A3
A3
A3
A3
A3
A3
4.88
4.56
4. 56
(4.10)
(4.10)
(4.33)
(4.33)
(5.29)
(4.10)
(4.10)
4.87
Note: 1. Data included in ( ) are estimated
2. The Dodge 440 CID engine replaced the 413 CID on 1/1/73.
3. GVW is in thousands of pounds. GCW is in pounds.
-------
only one model that exceeds it (the Chevy/GMC K10/K15 with, a 4, 900 to
6,200 Ib. GVW range). Thus the 6,000 and 10,000 Ib. levels represent
clear dividing lines between vehicles according to gross vehicle weight.
The second point also relates to weight; the gross curb weight
(GCW) of the vehicle. Vehicle curb weights are seen to be below 5, 000 Ibs.
for the majority of the vehicles shown in Table 2.2. Thus, if EPA ultimately
follows the current LDV certification practice 'of adding an incremental
payload to the vehicle curb weight to specify an inertia (test) weight, a
large fraction of the vehicles would be tested within a 6, 000-lb. limit
assuming weight increments of 500 to 1, 500 Ibs. Test weights for medium
duty vehicles would thereby overlap the test weight range of light duty
vehicles to a large extent.
Automobile manufacturers generally use the same basic
engine families in both light duty vehicles and medium duty trucks as
identified in Table 2.2. Engine families are defined as comprising engines
which share a common engine block casting and an identical cylinder
arrangement, bore spacing and deck height. Within an engine family,
engines may have different displacements resulting from, different bore
and/or stroke dimensions. Horsepower ratings of engines with identical
displacement may vary due to changes in carburetion, compression ratio,
cam design, etc. A comparison between engines used in passenger cars
and medium duty trucks for each of the major manufacturers is given in
Appendix A-l. In general, most of the engines identified in Table 2. 2
have direct counterparts in the light-duty vehicles. Except for a few cases,
these engines are identical internally with the same camshafts, heads and
compression ratios. For the 1973 model year, the medium-duty engines
are equipped with fewer external control devices for emissions and are rated
at slightly higher horsepower levels.
Transmission and axle ratio information presented in Table 2.2
represents the most popular (by sales) combination for each vehicle.model
2-19
-------
and engine combination. In cases where such data were not provided by
the manufacturer, an estimate was made based on a comparison with other
comparable models. Axle-ratio options for the medium-duty trucks over-
lap those available for light-duty vehicles to a small degree. Reflecting
higher vehicle weights, the MDV generally use a higher ratio axle.
There appears to be a trend toward the use of automatic
transmissions in vehicles which use the larger CID engine options. Motor
home units are all equipped with automatic transmissions to promote ease
of driving. Large CID engines are common in motor home applications
and reflect the need for additional power to achieve acceptable performance
•with the high GVW ranges of these vehicles.
A vehicle parameter found to be useful by the manufacturers
is the ratio N/V (engine rpm per vehicle mile per hour). Other factors
being equal for a given vehicle, it would be anticipated that a significant
change in this ratio would have a pronounced effect on baseline emissions
(as well as vehicle performance). Comparable information is presented
in Figure 2.3 which graphically shows the relationship among tire diameter,
axle ratio and GVW. As indicated in the figure, dividing the axle ratio by
the tire diameter gives a number proportional to N/V. A rectangle is
drawn bounding the available tire diameter and axle ratio combinations
within a given GVW range. The variation in engine revolutions per mile
within any one weight group can be substantial (about 38% in the 6, 000 -
10,000 Ib. GVW range). Significant is the fact that the 6, 000 - 10, 000 Ib.
grouping is fully isolated from both the 11, 000 - 15, 000 Ib. and 14, 000 -
16, 000 Ib. groups which show some overlap in the tire diameter - axle
ratio combinations used.
2.3.3 Sales
Sales data are required in establishing vehicle populations and
population trends which in turn impact on total pollutant emissions which
2-20
-------
tSJ
I
40
38
O 36
. 34
32
30
28
567
NUMERICAL AXLE RATIO
--40
-- 38
33
m
-36 P
0
--34
•\- - 34
NOTE: BASED ON 1973 FORD MODELS.
Figure 2.3 RELATIONSHIP BETWEEN TIRE DIAMETER, AXLE RATIO, AND GVW
FOR MEDIUM DUTY VEHICLES
-------
can be attributable to these particular groups of vehicles both now and in
the immediate future. A summary of factory sales for the past decade
is given in Table 2. 3 according to GVW. These data provide a perspective
and overview of the relative ranking of the 6, 000 - 10, 000 Ib. GVW and
10,000 - 14,000 GVW vehicle categories compared with the entire spectrum
of motor vehicles classified as trucks and buses. The 6, 000 - 10, 000 Ib.
GVW group is by far the most populous if the light-duty group of trucks is
excluded. There has been an essentially unbroken upward trend in the
sales of this weight class of vehicle. While the sales in the 10, 000 - 14, 000
GVW group remained static, and at a very small fraction of the 6, 000 -
10, 000 GVW group, for a period of eight years, a strong surge in sales
has taken place in since 1970. This effect is considered to be directly
related to the rapid increase in motor home sales in this period of time.
A further breakdown of sales by body style and GVW for 1967 -
1972 is presented in Table 2.4. A summary of sales of recreational vehicles
is also included. Probably the most striking feature of these data is the
popularity of the pickup truck which has accounted for well over 55% of
the total annual sales of the two weight groups included in Table 2. 4. The
market share of the multi-stop and chassis groups has been substantially
stable while the van group has captured a steadily rising share of the sales
(3% in 1967 to 14% in 1972).
Sales data for recreational vehicles are shown over the same
period of time. These figures represent considerable rounding off since
they are the sums of similarly rounded monthly data. Truck campers have
registered a steady growth in sales. On the other hand, motor home sales
have doubled over the previous year in both 1971 and 1972. A further
breakdown of motor home sales by type is given below.
Conventional Van Chopped Van
1971 37,795 9,457 12,732
1972 64,600 23,800 28,400
2-22
-------
N)
UO
Table 2.3
Factory Sales of Trucks and Buses by G.V.W.
Total
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
6,000 .
& Less
677,804
836, 129
919,663
1,058,211
1,020, 158
899,986
1, 136,059
1, 121,222
950,252
1, 196,544
1,414,551
6,001-
10,000
213, 050
246,650
250,204
294, 178
296,957
289,835
385,803
405, 108
401,592
444,052
539,052
10,001-
14,000
8,503
5,679
5,804
5,020
7,485
5,207
4,646
7, 161
7,353
16, 007
43,989
14, 001-
16, 000
27,495
28,450
24,234
25,751
21,286
16,499
17,495
13,491
9,979
14,871
9,945
16,001-
19,500
142, 163
145,298
142,277
144,449
125,473
88,213
79,436
78, 105
59,205
58,042
28,080
19,501-
26,000
93, 138
109,570
104,499
109,625
124,361
123,934
141,264
147,405
124,554
132, 197
182,058
26,001-
33,000
35, 153
32, 186
29,613
39,968
44,337
37,960
41,814
33,304
38,451
36,441
42,213
Over
33, 000
42,862
58, 746
64, 159
74,603
91,027
77,828
89,561
117, 383
101,054
110,735
141, 127
Total
1,240, 168
1,462,708
1,540,453
1,751,805
1,731,084
1,539,462
1,896,078
1,923, 179
1,692,440
2, 053, 146
2,446,807
Source: MVMA
-------
TABLE 2.4 ANNUAL U. S. DOMESTIC FACTORY SALES*1)
6,000-10, 000 LBS. AND 10,000-14,000 LBS. GVW VEHICLES
Body Style 1973(3) 1972 1971 1970 1969 1968 1967
Pic kup / C ampe r
(6K-10K)
Van/Pass. Van*/panel
(6K-10K)
Multi-Stop (6K-10K)
(10K-14K)*2)
>
ro
i
ro Chassis (6K-10K) 1
*" (Cab, Cowl, Bare)
(10K-14K) J
Totals*4)
355, 129
48.4%
75,727
10.3%
) 150,993
\ 20.6%
I
151, 316
7 o i.ojn
L \J . O /o
733, 165
345, 117
59.2%
83,614
14.3%
23,339
4.0%
41,528
7.1%
87,432
15.0%
2,370
0.5%
583,400
273,406
59.4%
64, 048
13.9%
33,612
7.3%
16, 007
3.5%
72,966
15.8%
NA
--
460,039
215,431
57.4%
46, 048
12.3%
32,431
8.6%
3,376
0.9%
74,221
19.8%
3,977
1.1%
375,484
247,466
64.9%
13,771
3.6%
38, 126
10.0%
4, 183
1.1%
74,978
1 9. 7%
2,978
0.8%
381,502
256,566
70. 1%
8,087
2.2%
27, 141
7.4%
1,915
0.5%
69,682
19.0%
2,661
0.7%
366, 052
173,700
64. 5%
7,379
2.7%
25,969
9.6%
2,582
1.0%
59,768
22.2%
NA
--
269,398
RECREATIONAL VEHICLES*5)
Truck Camper
Motor Home
110,000
116, 800
107,200
57,200
95,900
30,300
92,500
23, 100
79,500
13,200
61,600
9,050
Note: Motor Homes are included in the multi-stop and chassis groups
(1) MVMA FS-20 Summary Sheets
(2) These data are inferred
(3) Manufacturer's estimates (pickup/cab chassis data in some cases split 0.78/0.22)
(4) Subject to error due to multiple listing of a vehicle on FS-20
(5) "Recreational Vehicle Facts and Trends"
-------
These data dramatically emphasize the importance of the truck/camper
and motor home in the current sales of medium-duty trucks. Since the
majority of the campers and essentially all of the motor homes have a
GVW in the 6,000 - 14,000 Ib. range, it is seen that in 1972 40% of the
medium-duty truck sales were accounted for by the recreational vehicle.
This figure may be high since some of the demountable camper units may
have been purchased for retrofitting to other than new trucks. Nevertheless,
even discounting for this possibility, the percentage will still be high.
Sales projections for 1973 represent the sum of the manufacturers'
own estimates and combine data from Chrysler, Ford, General Motors,
and International Harvester (no data were provided by Ford for motor
home chassis sales projections). In a number of cases, the sales
projections supplied by a company were for models which included both
pickup and chassis-type body styles. In these cases, the composite sales
data were apportioned as follows: pickup 78% and chassis 22%0 This ratio
appeared to be consistent with similar data from other manufacturers whose
sales were given by individual body style. This mix is probably not constant
from one company's sales to another and may account for the rather low
share of the market assigned to pickups for 1973 (see Table 2. 4).
Manufacturers projected sales for their medium-duty truck
engines for 1973 were obtained and are summarized in Table 2. 5. The
data are aggregated according to four general classifications: (1) sixes,
(2) small eights, (3) intermediate eights, and (4) large eights. While
sales data for individual engine families for each manufacturer were fur-
nished, the format of Table 2. 5 is used to preserve the confidential nature
of these data in accord with the manufacturers' requests.
2-25
-------
TABLE 2. 5
Projected 1973 Sales of Medium Duty Truck Engines
Engine Classification CID Sales
Sixes 225-300 44,000
Small Eights 302-318 100,000
Intermediate Eights 330-360 498, 000
Large Eights 390-454 100,000
Intermediate-sized eight cylinder engines are seen to be the
most popular for the medium duty truck group by a large margin. The
bulk of the sales in this engine group are attributable to the 350 and 360
CID engines made by General Motors and Ford, respectively. Six-cylinder
engines are seen to be a minor factor.
A graphical summary of vehicle sales, past and future, is shown in
Figure 2.4. Separate sales curves are given for all vehicles in the range
of 6, 000 - 10, 000 Ibs. GVW and 10, 000 - 14, 000 GVW. A rapid upturn
in sales has taken place in both weight categories starting in 1970. A
composite curve of sales of all motor homes is also presented and exhibits
a rapid rise starting in 1970. Sales projections through 1980 are based on
an extrapolation methodology which is discussed in Section 3. 0 of this report.
Projections for motor home sales are especially hazardous because of a
limited history of sales and the fact that we are currently in a rapidly
expanding market for these vehicles. A leveling-off of sales is estimated
after 1974. Motor home sales and sales of vehicles in the 10,000 - 14,000
Ib. GVW category are felt to be highly correlated since the former is
considered to dominate the latter.
2. 3. 4 Usage
Emissions levels generated by a vehicle are affected by the
type of usage to which a vehicle is subjected. Factors such as load carried,
2-26
-------
800
700
600
co
Q
CO
O
co
O
I
LU
500
400
300
200
100
ESTIMATED
ACTUAL
HOMES 6-14 K
VEHICLES 10-14 K-LB GVW
1962 64 66 68 70 72 74 76 78 80
Figure 2.4 MEDIUM DUTY VEHICLE SALES
2-27
-------
trips per day, daily mileage, route followed, etc. are all important elements
in the emissions equation. In isolating vehicle types or vehicle subgroups
which may have unique emissions characteristics and in validating a range
of weights by which to characterize a medium-duty category of controlled
vehicle, information on vehicle usage is a useful input.
A review of readily available literature, References 1-5, showed
that data on the usage of vehicles in the 6, 000 - 14, 000 Ib. GVW range are
quite limited and often not directly relevant to these immediate needs. The
following specific deficiencies were noted:
vehicle classification by nonuseful GVW ranges; ie. ,
under 10, 000 Ibs. , 10, 000 - 20, 000 Ibs. , etc.
use of vehicle population samples unique to specific
urban areas and atypical of the national average.
dated information (in one case a decade old) based on
a non-current mix of vehicles
limited information on daily usage by vehicle type.
A summary of the more useful findings follows.
Reference 4 is an extensive compilation of statistical survey
data related to truck usage. A few significant conclusions, pertinent to
this program, are drawn from that report. The study finds that the majority
of motor trucks are used within an area in the immediate proximity of
their home base of operations. Typically, only 2% of all trucks regularly
travel more than 200 miles from the point of trip origin. Nearly 73% of
all light truck movements are local as contrasted with 20% for heavy units.
"Light trucks" are defined in Ref. 4 (and in most vehicular surveys) as
including 2-axle, 4-tire trucks with payload capacities of one-half to one
and one-half tons and with a GVW less than 10,000 Ibs. The principal
findings are that motor truck usage, like passenger car usage, tends to
concentrate in urban areas and that there is a clear difference between
light trucks and heavy trucks (GVW > 10, 000 Ibs. ) in their usage. Light
2-28
-------
trucks are predominantly urban oriented. Based on statistics obtained by
pooling survey data from 11 urban areas, the light truck accounted for (on
an average daily usage basis) 72% of all truck trips, 65% of all truck miles,
and 96% of all trucks employed for personal use. Of the total daily one-way
trips made by light trucks, 27% were made without load. Of the trips with
load, cargo was transported on 45% of the light truck trips and 28% of the
trips were used to carry tools and goods related to a service function. The
light truck was found to average 28 miles and 5. 9 trips per day. Table
2. 6 (from Ref. 4) summarizes these data and provides comparable figures
for a medium-heavy truck class.
Reference 5 is a summary of a recently completed field survey
of commercial vehicles in the state of California. One of the groups of
vehicles surveyed was the "dual-purpose" variety as exemplified by the
following types:
pickups (including those equipped with campers,
covers, and shells)
station wagons
small vans (including panel type and those used as
house cars, mobile shops, etc.)
truck campers (body permanently installed)
motor homes, mobile homes and trailer coaches
Random sampling techniques were employed at 39 different
locations in the state to stratify the samples geographically and functionally.
Data were collected over a period of several months, over seven days of
the week and during 20 hours of the day. A total of 4, 938 vehicles were
included in the survey (the dual-use fleet in the state is approximated as
2. 5 x 10 ). The following synopsized features characterized the results:
Pickups represent the largest single group of dual-
use vehicles. Coupled with camper variations, they
represent over half of the sample population.
Approximately one-fourth of all pickups are equipped
2-29
-------
Table 2.6
AVERAGE DAILY TRUCK USAGE IN 11 URBAN AREAS'
TRUCK
CLASS
LIGHT £ 10,000 LB
MEDIUM-HEAVY >10,000 LB
TOTAL
TRUCKS
MAKING TRIPS
NUMBER _&
72.989 71.8
28.691 28.2
101.680 100.0
DAILY TRIPS
NUMBER %
608.606 67.7
289.810 32.3
898.410 100.0
DAILY
TRUCK-MILES
NUMBER %
2,075,660 65.3
1,104,742 34.7
3,180,402 100.0
DAILY MILEAGE
PER TRUCK PER TRIP
28.4 3.4
36.5 3.8
31.3 3.5
DAILY
TRIPS
PER TRUCK1
8.3
10.1
8.8
INJ
I
OO
o
REF. 4.
These values are for trucks making trips on a typical weekday. When related to all trucks registered in the urban area, the average is 5.9 trips per day,
since a proportion of the registered trucks are idle on any given day.
NOTE: The values are summations of trip values for the 11 areas shown in source.
SOURCE: Comprehensive transportation studies by Wilbur Smith and Associates in Albuquerque, New Mexico; Baltimore, Maryland; Baton Rouge,
Louisiana; Columbia, South Carolina; Lewiston, Maine; Little Rock, Arkansas; Manchester, New Hampshire; Monroe, Louisiana; Richmond, Virginia;
Sioux Falls, South Dakota; and Winston-Salem, North Carolina.
-------
with some sort of enclosure (camper, shell, canopy,
etc. ).
Panel and van trucks represented only 8% of the sample.
Over 85% of the vehicles were in the weight range
between 3, 000 and 6, 000 Ibs. Less than one-half
percent weighed over 8, 000 Ibs.
Approximately 30% of the vehicles carried no load
(this figure agrees remarkably well with the 21%
found by the Wilbur Smith study, Reference 4).
Usage data (trip purpose) was collected under four different headings:
commuting (home-to-work), business (work related), personal business
and personal (nonbusiness). Table 2. 7 summarizes the results for each of
several body types. Of special interest is the fact that the pickup with an
equipped camper is used very frequently (49. 5% of the time) for home-to-
work trips. Also, the specialized nature of use of the van and panel types
is demonstrated by the very high percentage of the trips that are work
related.
In summarizing the results of these two reports, note must be
made of the fact that trucks under 6, 000 Ibs. GVW dilute all of the data.
Despite this, it is clear that all trucks with a GVW limit of 10, 000 Ibs.
and less are urban oriented and act and operate in traffic very much like
the typical passenger automobile. Both references agree that this group
of light truck operates without load about 30% of the time. Pickup vehicles,
and their variants, are predominantly used for nonwork related purposes.
The Ethyl Corporation report (Ref. 3) presents the results of a
three-city survey* using trucks instrumented to record a time history
of engine load (manifold pressure) and engine revolutions. Unfortunately,
the entire GVW range of trucks was included within a small total sample
of vehicles. Consequently the number of vehicles within the GVW range
considered in this program was small and the number of different vehicle
*Detroit, Los Angeles, San Francisco
2-31
-------
I
OJ
Table 2.7
Distribution by Body Type and Trip Purpose
Body Type
Pickup
Pickup with Camper Shell
Pickup with Equipped Camper
Motor Home
Station Wagon
Panel
Van
Other
All Body Types - Percent
- Number
Percent Distribution
Home-to- Work-
Work Related
29.7
34.4
49.5
28.3
21.8
17.2
1.0
18.5
27.4
1,350
35.3
17.5
2.9
1.7
12.7
65.6
90.2
70.4
26.6
1,309 1,
by Trip Purposes
Personal
Business
18.5
18. 1
15.4
25.0
28.4
9.3
2.0
7.4
20.8
023
Personal
Non- Business
16.4
29.9
32.2
45.0
37. 1
7.9
6.9
3.7
25.2
1,245
All Trip
Percent
100
100
100
100
100
100
100
100
100
_
Purposes
Number
2,022
331
382
60
1,699
302
102
27
-
4,925
Source: Reference 5
-------
types correspondingly few. Further detractions to the utility of the data
result from the fact that only fleet-owned vehicles were involved and the
data are quite old (vehicle models sampled ranged from 1948 to 1962).
Despite these limitations the report does present data on such parameters
as mean speed, daily mileage, route type and load.
An analysis of usage was made using tabulated data from
Reference 3 with the objective of determining if there existed a basis for
differentiating among the following GVW groups of trucks: ^6, 000 Ibs. ,
6, 000 - 10, 000 Ibs. , 10, 000 - 14, 000 Ibs. and 14, 000 - 16, 000 Ibs. To
achieve a reasonably-sized sample, the data for all three cities were
pooled despite a demonstrated difference in vehicle usage among these
cities. Comparisons among these groups were made for each of the
following parameters: engine displacement, miles/day, percent total
engine revolutions in idle, percent total engine revolutions in cruising
mode, average mph and horsepower per 1, 000 Ib. load. Other operating
modes besides idle and cruise were evaluated in the original study, but
these two were selected since the largest fractions of the total vehicle
operating time were spent in these two modes. For each GVW group and
parameter the mean and standard deviation of the mean were calculated.
The results, shown in Figure 2. 5, plot the means and a vertical bar
(associated with each mean) whose length represents an interval equal to
two standard deviations of the mean. This type of presentation is inter-
preted as follows. If, by drawing a single line parallel to the horizontal
axis, all four vertical bars (within any one parameter group) can be
intercepted, then in a statistical sense, there is no basis for judging that
any one GVW group differs from another. Stated conversely, the samples
comprising each of the four GVW groups-are said to originate from the
same sample population. Thus, reference to Figure 2. 5 shows that there
is no basis for separation of vehicles by GVW within the set the data
analyzed except for the last parameter, hp/lK#, which does show statis-
tically significant differences. Since engines of the same approximate
mean displacement (hence horsepower) were used in all vehicles
2-33
-------
STATISTICAL SUMMARY
ENGINE DISPL. (IN.3) MILES/DAY
IDLE
% CRUISING
AVG. MPH
HP/K-LB
320
280
240
200
160
tSJ
1
OO
4^
120
80
40
n
'I1'
•
° ' 0 ^
160
140
Jl20
100
80
60
40
20
'hi
1 ' 1 1 1
t (O O '
16-
14-
12-
10-
8-
6-
. 4-
2-
40-
35
30
25
20
15
.10
5-
1 i 1 1 1— 1
t
-------
irrespective of GVW group, these differences are not unexpected. While
this finding is also not unexpected, it does verify the fact that engines
used in medium duty trucks are operated at a heavier loading than those
used in light duty cars or trucks,, This condition obviously will need to be
considered when emission controls and their effectiveness and durability in
medium duty vehicles are being analyzed.
An analysis was made also of the relation between vehicle loaded
weight and vehicle GVW (as given in Ref. 3 ) for vehicles up to 16,000 Ibs.
The data showed that all these vehicles, on the average, operated fully
loaded, i.e., at GVW ratings. This result is not consistent with the
Wilbur Smith study (Ref. 4) which found that "light" urban trucks operate
empty 50% of the time and, when loaded, carry an average load of 600 Ibs.
This same study (Ref. 4) also reports that 70% of all trucks are single
operations (individually owned). Several factors may explain these dif-
ferences: (1) the Ethyl study, because it required the use of instrumented
trucks, was forced to rely on a sample that was entirely "fleet" operated,
(2) it may be inferred that the loaded weight given referred only to the
value when the vehicle was operated with maximum load (i. e. , no-load or part
>fc
load situations were not noted), and (3) differences in test locale. Data
in Ref. 4 were obtained in medium-sized urban areas (see footnote to
Table 2. 6) whereas the Ethyl study was conducted within very large metro-
politan areas.
Reference 2 is a separate Wilbur Smith report on the CAPE-21
program which to date has produced no new data but rather assembled
and processed existing data on truck usage in the New York City and Los
Angeles areas. All of these data are for vehicles classified only by
number of axles and rear tires. For New York City, only 20% of the sample
of vehicles analyzed were within the 6, 000 - 14, 000 GVW range. While data
on number of daily trips, mean velocity and trip length were determined,
these figures are unidentifiable with vehicle body types. The Los Angeles
* Explicit information concerning the determination of vehicle loaded
weight is not given in Reference 3.
2-35
-------
data are even less useful since the survey started with vehicles with an
empty weight of 6,000 Ibs, As shown in Table 2.2, it is only the rare
vehicle in the 6, 000 - 14, 000 Ib. GVW group that has an empty weight
over 6, 000 Ibs. Consequently these references did not provide useful
data.
2-36
-------
2.4 Representative Vehicle/Engine Combinations
2.4.1 Selection
The selection of vehicle/engine/drivetrain combinations repre-
sentative of each of the five major groups identified in Table 2. 1 (pickup/
camper, van/passenger van, multi-stop, chassis and motor home chassis)
was performed in accord with the methodology discussed in Section 2.2. A
number of considerations entered into the selection process. These included
the extensiveness of usage of a particular combination, possible effects of
different combinations on emissions, the need to adequately represent the
GVW spectrum within any one group and the impact of these selections on
the economic analysis (Part B).
In the selection process the data summarized in Table 2.2
were extensively used. This tabulation identified the vehicles according
to make, model, axles, GVW range, GCW range, engine CID, horsepower,
transmission and axle ratio. This table, as initially published in a project
progress report (Reference 6), included the manufacturer's 1973 sales
projections for each engine/drivetrain combination shown. Omission of this
information in Table 2.2 is for proprietary reasons. The resultant list of
group representative vehicle/engine/drivetrain combinations that were chosen
is given in Table 2.7a. This listing as well as that of Table 2. 1 (vehicle grouping)
were subject to the approval of the EPA Project Officer.
This listing is broadly representative on several counts: (1) the
largest-selling models and engines are included, (2) the range of engine
displacements is adequately represented, (3) a wide GVW range is encom-
passed by the models selected and (4) all major manufacturers of medium
duty trucks are represented.
In the multi-stop group, the selection of the Chev. /GMC P30/P35
model with a small six engine (in a high GVW vehicle) was based on a desire
2-37
-------
I
00
oo
TABLE 2.7a GROUP REPRESENTATIVE VEHICLE-ENGINE COMBINATIONS:.
Physical Characterization - 1973 Models
GROUP
Pickup/ Camper
Van/Pass. Van
Multi-Stop
Chassis
MAKE
Chev./GMC
I-H
Ford
Chev/GMC
Chev./GMC
Ford
Ford
MODEL
C20/C25
1210
E300
P30/P35
C20/C25
F350
F500
AXLES
4x2
4x2
4x2
4x2
4x2
4x2
4x2
ENGINE
V8-350
V8-345
V8-302
16-250
V8-454
V8-360
V8-330
HP
155
144
139
100
240
148
137
TRANS.
A3
M3
A3
M4
A3
M4
M4
AXLE RATIO
4. 10
3.73
3.73
4.56
3.73
4. 10
5.83
Motor Home
Chassis
Dodge
M300/R400
4x2
V8-318
160
A3
4. 88
-------
to include a combination which might exhibit an unique emissions level due
to a high engine loading.
2.4.2 Emission Controls
Emission controls, either incorporated as engine modifications
or installed as add-on devices, were identified by reference to the
manufacturers' certification handbooks submitted to EPA. Controls installed
on 1973 models of the group representative vehicle/engine combinations
(Table 2. 7a) are shown in Table 2. 7b. All vehicles include crankcase emission
controls, however, only those vehicles marketed in the State of California
are equipped with evaporative emission control systems. While all engines
incorporate some types of modifications for exhaust emission control, since
they generally are derivatives of light duty engines, EGR or air injection is
only used on some engines sold in California. This strategy is necessary to
meet the combined HC + NOX standard of 16 gm/bhp/hr adopted by California
for 1973 models. A narrative-type description of the various control systems/
devices, which are only identified by their acronyms in Table 2. 7b, is given
in Table 2.8.
2.4.3 Baseline Emissions
In assessing the emission reductions possible by the addition
of new or additional control devices to medium duty vehicles, it is necessary
to define baseline emission data for each representative vehicle/engine com-
bination as a reference.
To measure the necessary emissions data, EPA chose to test
this category of vehicles using the basic 1975 Federal Test Procedure de-
veloped for light duty vehicles. In view of the usage data described in this
report for the medium duty vehicle, the use of the LA-4 driving cycle for
emissions determinations is justifiable and reasonable. The only ^variations
to the 1975 FTP are found in the determination of the vehicle inertia weight
and road load horsepower.
2-39
-------
TABLE 2,7b GROUP REPRESENTATIVE VEHICLE-ENGINE COMBINATIONS;
Emission Control Devices - 1973 Models
GROUP
MAKE
MODEL
ENGINE
EMISSION CONTROLS*
Motor Home
Dodge
M300/R400
V8-318
PCV
CAN
EM
NOTES
Pickup/ Camper
Van/Pass. Van
Multi-Stop
^ Chassis
O
Chev. /CMC
I-H
Ford
Chev. /CMC
Chev. /CMC
Ford
Ford
C20/C25
1210
E300
P30/P35
C20/C25
F350
F500
V8-350
V8-345
V8-302
16-250
V8-454
V8-360
V8-330
Crankcase
PCV
PCV
PCV
PCV
PCV
PCV
PCV
Evaporative
GMECS
CAN
CC
- -
GMECS
CC
CC
Exhaust
CCS 1
EM, EGR, 1 4 6
TLD
IMCO 1
CCS 2
CCS, AI 1 3
IMCO, EGR 1 4
IMCO 1
1 5 .
* See Table 2.8 for description of Emission Controls.
Notes: 1 Evaporative Controls only on California vehicles with fuel tanks ^ 50 gals.
2 This engine not sold in California
3 Air Injection (AI) only on California vehicles
4 Exhaust Gas Recirculation (EGR) only on California vehicles
5 Electronic Ignition on California vehicles, otherwise optional
6 Throttle Limiting Device (TLD) only on California vehicles
-------
TABLE 2.8 - EMISSIONS CONTROL DEVICES PRESENTLY USED
Abbreviation
System Name
System Description
PCV
AI
EGR
t\>
i
Positive Crankcase Ventilation
System
Air Injection System
Exhaust Gas Recirculation System
TLD Throttle Limiting Device
GMECS General Motors Evaporative Control
System
CC Carbon Canister
CAN CANister evaporative control
EM ^Engine Modifications
CCS Controlled Combustion System
IMCO IMproved COmbustlon System
A system which supplies fresh air to the crankcase through
the air filter and directs the blow-by gases into the intake
manifold through a spring-loaded metering valve.
A system consisting of an engine-driven air pump
which supplies fresh air to nozzles located in the exhaust
ports, completing combustion of hydrocarbons externally.
The systems usually incorporate some flow control devices
for better driveability.
A system which controls oxides of nitrogen (NO ) emissions
by recirculating a portion of the exhaust gases back into the
intake manifold. The plumbing consists of fixed orifices or
vacuum-controlled valves.
A system to limit the rate of closure of the throttle to pre-
vent excessively high manifold vacuum during deceleration.
All of these systems are evaporative emissions control
systems consisting basically of a charcoal or carbon filled
canister into which the hydro-carbon vapors from the gas
tank and carburetor are directed. They are stored here
until the engine is started at which time they are purged
into the intake manifold.
These systems consist mainly of modifications and recali-
brations made on basically unchanged pre-emission control
engines. The carburetor and choke are modified, the spark
advance curve is altered, the compression ratio is lowered,
the head design is altered, a system to pre-heat intake air
is installed, the camshaft profile is altered, etc.
-------
Inertia weight rounded to the nearest 500 Ibs. is obtained by the
addition of a weight increment to the vehicle GCW based on the vehicle payload
capacity. The weight increment is determined from the following schedule.
Payload (GVW - GCW) Weight Increment
2000 Ibs. 500 Ibs.
2001 Ibs. - 4000 Ibs. 1000 Ibs.
4001 Ibs. 1500 Ibs.
Road load horsepower is based on the vehicle inertia weight (Iw) and
*
given by the following linear equation where I is in units of pounds.
Road load horsepower = 0. 0096 I - 30. 3
Emissions data provided by EPA were from three sources: (1) an
EPA in-house program, (2) Southwest Research Institute (SWRI) and (3) Auto-
motive Engineering Systems, Inc. (AESI). Data on a total of 122 vehicles were
received. A tabulation of these emissions data is given in Appendix A-2. In
the appendix, the information is identified according to source, vehicle make,
model year, body type, GVW, GCW, inertia weight, engine and the average
emissions in grams per mile for HC, CO, CO and NO . In addition, the number
Cj x.
of tests averaged and the state of tune of the vehicle are noted. During the early
stages of these experimental programs, the vehicles were tested in an "as-
received" condition, however the later groups of vehicles were tested with the
engine dwell, timing and idle adjusted to specifications. Subsequent to the
submittal of the draft of this report some additional emissions data were supplied
by EPA. Usage of these new data in performing additional analyses requested
by the Project Officer is discussed in a later part of this section.
A summary of the baseline emissions data for the selected group
representative vehicle/engine combinations is shown in Table 2.9. It can be seen
that for two of the categories there were no test data at all while for some others
only few test points were available. Even to accumulate these meager totals it
was necessary to use data from untuned and older vehicles.
*
The procedural details employed in collecting these emissions
data do not necessarily represent the final test procedures that
may be specified by EPA for the medium duty category of vehicles.
2-42
-------
TABLE 2.9
GROUP REPRESENTATIVE VEHICLE-ENGINE COMBINATIONS:
Exhaust Emission Levels - Equivalent 1975 FTP
GROUP MAKE
Pickup/Camper Chev./GMC
I-H
Van/Pass. Van Ford
Multi-Stop Chev/GMC
i
^ Chassis Chev./GMC
Ford
Ford
Motor Home Dodge
MODEL
C20/C25
1210
E300
P30/P35
C20/C25
F350
F500
M300/R400
ENGINE
V8-350
V8-345
V8-302
16-250
V8-454
V8-360
V8-330
V8-318
GVW
RANGE
6200-
10000
6100-
7500
6050-
7600
10,000
10,000 -
11,000
TEST WGT.
RANGE
5000-
7500
5000-
6500
5000-
6500
8200
8,000
9,000
MEAN EMISSION LEVELS (g/mi) NOTES
HC CO NO
4.57 40.57 7.81 1
5. 62 66. 12 5. 06 4
5..8S 54.69 5.82 ^
*
12.85 116.28 6.93 3
*
8.84 142.29 13.23 5
No Test Data Available on These Engines
Notes: 1 Twelve vehicles (1-1970, 4-1971, 7-1972), average of 26 tests (25 CO)
2 Eight vehicles (2-1971, 2-1972, 4-1973), average of 16 tests
3 One vehicle (1971), average of two tests
4 Two vehicles (1-1971, 1-1972), average of two tests
5 Three vehicles (1-1970, 1-1972, 1-1973), average of eight tests
-------
A decision was made to exclude all data from vehicles older than the 1970
models in forming baseline averages.
A review of the emissions data in Table 2. 9 and all the other test
data available on the medium duty trucks indicated that differences between engine/
vehicle combinations could not be ascertained. The large scatter in the emis-
sions data whether due to vehicle state of engine adjustment, vehicle-mileage,
vehicle age or other factors, did not permit such discrimination to be made.
This statement, however, should not be interpreted to imply that no such
differences exist. The data do tend to support the observation that vehicle
emissions increase with the test weight (or inertia weight) of the vehicle.
The limited data shown in Table 2. 9 agree superficially with this contention,
the chassis and motor home chassis vehicles showing, on the average, in-
creased emissions with test weights in the 8, 000^9, 000 Ib. range.
As a consequence of this situation, the methodology based on
engine/vehicle combinations could not be pursued further. Rather, the emis-
sions data were reviewed to ascertain what differentiation among vehicles
was possible.
In making use of the emissions data base given in Appendix A-2,
the following decisions were made:
use only data from tuned 1972-1973 model vehicles
if possible
if necessary to use data from untuned vehicles, then
include 1970 and 1971 models only
exclude data from low-mileage, unstabilized (green
engine) vehicles.
A serious limitation of the data base is the concentration of the data at a
test weight of 5, 000 to 5, 500 Ibs. Where data at higher test weights exist,
they are almost entirely from motor homes. No data are available at a
test weight exceeding 10, 000 Ibs.
2-44
-------
A series of linear regressions were performed on various subsets
of the data with, mass emissions per mile regressed on inertia weight. A
simple linear regression analysis was performed on the emissions data for
all tuned 1972/1 973 trucks and motor homes. A total of 40 test vehicles was
available that met these criteria, 32 trucks and 8 motor homes. This sample
of vehicles spanned the range of test weights from 4,500 Ibs. to 8, 500 Ibs. with
the motor homes concentrated at the upper end. Using the regression equations
thus determined, emissions data were calculated at a test weight of 10, 000 Ibs.
and compared with emissions actually measured from a few untuned and older
trucks at this weight. The calculated emissions were found to be very much
larger, especially for CO and NO levels, than the measured results. Because
X
of the poorly distributed inertia weights, it was necessary to use a data sample
that included all 1970-1973 vehicles, both tuned and untuned, to extend the
range of inertia weights encompassed. Results of this analysis on a sample
size of 85 vehicles indicated that the inclusion of emissions data for only nine
motor homes, increased the slope of the regression lines significantly upward
*
(compared to trucks-only data) for CO and NO emissions. Consequently, a
X
regression analysis was made for only the truck data, Results are given below.
Regression Equations - Trucks Only (76 Points)
MHC = 0.526 I + 2. 38
w
M
CO = 7.09 I 4-19.8
w
M
NO = 1.02 I + 1.61
x w
M. = grams/mile of pollutant i
I = inertia weight, thousands of Ibs.
w to
The motor homes appear to require separate consideration. Because of the small
data base for motor homes (only 9 samples ), a limited test weight range (7, 500 -
It should be noted that 7 of the 9 motor homes were tested at 8500 Ib.
Iw or more; there were only four trucks at this same Iw included in
this data set.
2-45
-------
9,000 Ibs. ) and a wide scatter in the emissions data, a regression analysis
was not considered justifiable. Consequently a simple average of these data
was taken as the most reasonable treatment of the data that could be made.
These results are shown below:
AVERAGE EMISSIONS-MO TOR HOMES (9 SAMPLES)
HC CO NOX . Average Test Weight
gm/mi gm/mi gm/mi Ibs.
7.82 125.71 13.07 8,400
For purposes of comparison, a second set of regression equations
was determined per request of the Project Officer utilizing a different data
base as specified by EPA. This data base was determined in accordance with
the following specific instructions:
a use all 1970 - 1973 trucks and motor homes, tuned
*
and untuned, excluding 1973 California (AESI)
vehicles and EPA vehicle #49 (see Appendix A-2).
treat all EPA vehicles tested at more than one inertia
**
weight as a separate vehicle at each weight tested
treat all vehicles tested twice (in both tuned and
untuned condition) as separate vehicles (four SWRI
and nine AESI vehicles).
*
There appears to be no significant difference in measured emissions
from the tuned vs. untuned vehicles for this particular data set.
** Although not shown in Appendix A-2, the first eleven EPA vehicles
were each tested at four different inertia weights.
2-46
-------
• use emission data (from 13 additional medium duty
vehicles (1971 - 1973) provided by EPA (not shown
in Appendix A-2).
The regression equations for this data set are given below:
REGRESSION EQUATIONS-TRUCKS AND MOTOR HOMES
(135 samples)
MHC =
Mco =
M.T_ =
NO
X
0.5551 +
w
11. 20 I
w
1. 35 I
w
1. 94
8. 19
0.56
A plot of the two sets of regression lines for HC, CO and NO
X
emissions for trucks alone and trucks/motor homes combined is shown in
Figures 2.7 through 2.9. Included for the trucks/motor homes regression
>'
-------
18
00
cc
o
X
16
14
12
10
A-A REGRESSION LINE FOR TRUCK (76 POINTS)
C-C REGRESSION LINE FOR TRUCKS AND
MOTOR HOMES (135 POINTS)
B-B.D-D 95% CONFIDENCE BOUNDS ON REGRESSION
LINE C-C
678
Iw - INERTIA WGT., K-LB
10
Figure 2.7
REGRESSION LINES OF HC EMISSIONS ON INERTIA WEIGHT
FOR TRUCKS AND TRUCKS/MOTOR HOMES COMBINED
2-48
-------
/
/'
>c
2 100
x
50
40
.--,-X-r-
30
20
10
0
• X i
:..X---..! --• •"
b^ : :
[ j. I \-
-^L
FOR
£rREGRESS,ON UNE FOR TRUCKS ,76 POINTS,
« KoR«^,j?r ;;;EKION
95% CONFIDENCE BOUNDS ON REGRESSION
B-B.D-D
C-C
10
TW
- INERTIA WGT., K-LB
2-49
-------
18
16
14
12
d 10
w
cc
CJ
X
o
A-A
C-C
B-B,D-D
REGRESSION LINE FOR TRUCKS (76 POINTS)
REGRESSION LINE FOR TRUCKS AND
MOTOR HOMES (135 POINTS)
95% CONFIDENCE BOUNDS ON REGRESSION
LINE C-C
6 7 8
Iw - INERTIA WGT., K-LB
10
Figure 2.9 REGRESSION LINES OF NOX EMISSIONS ON INERTIA WEIGHT
FOR TRUCKS AND TRUCKS/MOTOR HOMES COMBINED
2-50
-------
2. 5 Validation of GVW Limits
The results of the studies concerned with vehicle mechanical
aspects, usage, sales and emissions, which have been discussed in the
preceding sections of this report, provide a basis upon which a selection
of suitable GVW limits for a controlled category of medium duty vehicle
can be considered.
This project was initiated with two explicit assumptions (as
incorporated in its statement of work): (1) an equivalent 1975 FTP would
be used in measuring exhaust emissions from the MDV group and (2)
emission control technology from the LDV category was directly adaptable
to the MDV group and an analytical prediction of potential emissions
reduction thereby possible was feasible. Implicit in these assumptions
is the appropriateness of the LA-4 driving cycle in reflecting usage of the
MDV and the similarity in engines/transmissions/axle ratios between the
LDV and MDV. In selecting limits therefore, every effort should be made
to insure that the validity of these assumptions is reinforced to the maximum
extent consistent with other restraints.
A basis for making judgments on the GVW limits exists in terms
of the following four aspects of the vehicles included in the medium duty
category: population, physical characteristics, usage and emissions. A
simplification among the vehicle types included in this category is readily
made. Usage information and emissions data both identify the motor home
as a unique member of the medium duty group of vehicles. Since it must
be accorded special consideration, its role in influencing GVW limits for
the general group of medium duty vehicles can be considered minimal.
2-51
-------
Consider the lower limit of the GVW range of a medium duty
category. One possibility admits of the extension of the light duty class
of vehicle to include a GVW range in excess of the present limit of 6,000
Ibs. Two factors rule strongly against this approach. First, the 6,000 Ib.
level of GVW has been shown earlier to be a sort of ^watershed level at
which certain vehicle models reach their maximum weight ratings and
others begin with their minimum ratings. In the case of 1973 models,
only one model vehicle, in fact, was found to violate the 6, 000 Ib. GVW
"barrier". This factor is important in the certification process if given
models of vehicles are to avoid certification under two different procedures.
Once this barrier is broached, the next reasonable limit is 10,000 Ibs.
Second, the emissions data are seen to be a function of vehicle weight. Thus
major revisions to emission standards applicable to this "expanded" LDV
category would be required. Both these considerations would appear to
offer serious disadvantages to any alteration of the weight limits of the
light duty vehicle category. Consequently, it is concluded that the lower
limit of the medium duty class of vehicle should be set at 6,000 Ibs. GVW.
Factors affecting the selection of an upper GVW limit do not
provide a basis that leads clearly to a single choice. Looked at from the
standpoint of GVW ranges of individual models, two alternatives appear to
be reasonable; 10,000 Ibs. and 14,000 Ibs. Based on 1973 models, only
one vehicle model spans the 10,000 Ib. level while several broach the
14, 000 Ib. limit.
Usage data, with the limited scope, do not lead to any
discrimination between trucks in the 6, 000 to 10,000 Ib. group and those
in the 10,000 to 14,000 Ib. group. On the other hand, dual-purpose
2-52
-------
*
vehicles , such as pickups, vans, passenger vans, are entirely located
within the 6,000 - 10,000 Ib. GVW range. Dual-purpose vehicles would
obviously be used and operated much more like passenger cars than purely
commercial vehicles. It would also be granted that the 6,000 - 10,000 Ib.
GVW vehicle is more closely akin the LDV than is the 10,000 - 14,000 Ib.
vehicle.
Sales data clearly show the preponderant domination of the
6,000 - 10,000 Ib. group. While sales in the 10,000 - 14,000 Ib. group
have shown large increases in the last several years, the evidence
attributes this growth to motor homes alone. Thus a relatively small
number of additional trucks would be included if the upper GVW limit
were extended to 14,000 Ibs.
The evidence is felt to favor the choice of 10, 000 Ibs. GVW
as an upper limit for the medium duty group of vehicles. An important
advantage accruing from this limit is the flexibility afforded in setting
emission standards. Because of this relatively restricted GVW range, it
becomes feasible to consider setting a single numerical standard for each
pollutant for this class vehicle. For example, the standards could be set
based on the emissions performance achievable by vehicles at the upper
end of the GVW range with the presumption that the lighter vehicles would
at least meet, or improve upon, these values.
Clearly, there is no compelling evidence why the GVW limit
should not be set at 14,000 Ibs. One result would be that vehicles less
like those in the LDV category would be included and a graduated or,
* Currently classified in the heavy duty category
2-53
-------
possibly, a two-tier emission standard would be required because of the
extended weight range. Very few emission data points are presently
available upon which an assessment of emission levels could be made for
vehicles in the 10, 000 - 14, 000 GVW range.
The population of motor homes is less stratified by weight than
it is for trucks. Sales data and projections indicate a popularity of the
10, 000 - 14, 000 Ibs. GVW motor home that cannot be ignored. Accordingly
the GVW limits for motor homes should include the range from 6, 000 to
14, 000 Ibs. Because the motor home (1) is not used in urban areas or
central business districts (2) is driven only about 5,000 miles per year
(RVI publications) as compared with 10,000 miles per year for medium
duty trucks (Reference 1) and (3) exists in considerably fewer numbers
than the medium duty truck, a less demanding emission control strategy
may be considered. For example, a single emission standard could be
used for all motor homes irrespective of weight over the 6, 000 - 14, 000
Ib. range. This standard would need to be set to accommodate the
vehicles at the high end of the GVW range.
2-54
-------
2. 6 Emission Reduction Potential
There are two essentially different approaches that can be followed
to reduce exhaust emissions from medium duty trucks. One approach involves
modifications of the conventional gasoline engine and/or treatment of its ex-
haust products using one of a number of emission control systems. The
second approach is to replace the conventional gasoline engine with another
power plant, such as the diesel or three-valve carbureted pre-chamber
(CVCC) engine, which has lower baseline emissions and may or may not re-
quire an emission control system in order to meet specified emissions standards.
Each of these approaches to reducing emissions from medium duty trucks is
discussed in the following sections.
2.6.1 General Approaches for Reducing Medium Duty Truck
Emissions
2.6. 1. 1 Reduction of Emissions from Conventional
Gasoline Engines
The HC and CO exhaust emissions from the conventional gasoline
engine used in most medium duty trucks have been significantly reduced over
the past five years by a series of engine modifications including timing changes,
carburetor A/F ratio changes (leaning), cylinder piston and head shape changes,
and a compression ratio reduction. These modifications have also occurred
in truck engines because essentially the same engines are used in trucks as
passenger cars for which federal emissions standards have been progressively
tightened since 1968. The baseline engines for the present truck study are
those used in 1972-73 trucks outside of California (i. e. , no EGR). The cor-
responding baseline emissions are those from trucks using the baseline engines.
Correlations of the baseline emissions as a function of truck inertia weight
have been previously discussed in Section 2.4. 3. Emissions control systems
2-55
-------
(further engine modifications and exhaust gas treatment devices) are applied
to the baseline engines and their effectiveness referred to the baseline emissions,
The emissions control systems to be evaluated for medium duty
truck applications are listed in Table 2. 10. The various components in the
control systems for gasoline engines are identified and described briefly in
Appendix A-4. The systems chosen for the most part have been developed and
tested to a reasonable extent for light duty vehicle applications. They offer
as a group the capability of achieving a wide range of emissions reductions.
This was necessary in the present study because emissions standards for
medium duty trucks have not been set and it was desired to investigate in de-
tail the emissions reductions/cost tradeoffs of a cross-section of control sys-
tems. In later sections, the emissions reductions that can be expected using
each of these systems on conventional gasoline engines are studied as well as
the effects of the control system on fuel consumption and vehicle driveability.
2.6. 1.2 Alternative engines
The exhaust emissions from medium duty trucks can also be re-
duced by replacing the conventional gasoline I. C. engine with a power plant
with lower baseline emissions. As indicated in Table 2. 12, a variety of
power plants are being developed which could be considered for use in MDV.
These power plants vary widely in their status-of-development and cost, size,
and fuel consumption relative to the gasoline engine which they would replace.
In the present study, the only alternative power plants considered were the
light weight diesel and the three-valve carbureted pre-chamber (CVCC) engines.
Both of these engines have attractive HC and CO emissions and fuel economy
characteristics. In addition, the NO emissions of each can be reduced to a
X
relatively low level ( 1-1.5 gm/mi) using EGR. The gas turbine engine was
not included because in its present design it has a high NO emission level
(3-4 gm/mi) and poor fuel economy at part-load conditions which are regularly
2-56
-------
Table 2. 10: Emission Control System s for Conventional
Gasoline I. C. Engines
Number
System
EM'
2
3
4
5
6
7
8
EM° + El + FC + AI + EGR
EM° + El + 1C + QHI + AI + EGR
EM° + El + 1C + QHI + EGR + AI + OC
EM° + El + 1C + QHI + EGR + RC + AI/CAI + OC
EM° + El + EFIC + EGR + RC/OC
EM° + El + 1C +QHI + EGR + LTR
EM° + El + FC + EGR + AI + RTR
EM° + El + FIG + IQHI + AI + EGR
(a) 1972 engine modifications included in the baseline engine
configuration
Component Identification
El - Electronic Ignition
FC - Fast Choke
QHI - Quick Heat Intake
AI - Exhaust Manifold
Air Injection
EGR - Exhaust Gas Recircu-
lation
1C - Improved Carburetion
CAI - Air Injection Ahead of
Catalyst
OC - Oxidizing Catalyst
RC - Reducing Catalyst
AI/CAI - Controlled Air Injection
EFIC - Electronic Fuel Injection
and Control
RC/OC - Three-way Catalyst
LTR - Lean Thermal Reactor
RTR - Rich Thermal Reactor
FIC - Further Improved Carburetion
IQHI - Improved Quick Heat Intake
2-57
-------
Table 2. 11: Control
Code
Letter
A
B
C
D
1-6,
V-8,
V-8,
V-8,
Engine
CID 250
CID 318
CID 360
CID 454
System Configurations
Control Combinations
1-8
1-8
1-8
1-6,8
Reactor Volumes and Configurations
Catalytic Reactors
Engine
A
B
C
D
No. of Oxid.
Catalyst
1
1
1
2
Total Vol.
of OC (in 3)
150*
225
225
300
No. of
RC
1
2
2
2
Total Vol. in
RC (in 3)
*
200
250
250
300
All catalysts used with low lead gas ( < . 05 gm/gal)
and they must be replaced every 25, 000 miles.
Thermal Reactors
Engine
No. of Reactors
Total Vol. (in )
A
B
C
D
1
2
2
Not applicable
200
240
270
,**
* Pellet, noble metal type (about 2/3 this size if monolith used).
**Reactor volume is 75% of CID. This could vary between 70% and
100% of CID depending on design.
2-58
-------
Table Z. 1Z: Pollution, Cost, and Fuel Consumption Characteristics of
Alternative Automotive Propulsion Systems
Propulsion System
Pollution
Cost
NO
x
Fuel
Consumption Ref
6
1
1
6
1
1
10
1
3
1
1. 25
1.Z5
1
1. 1Z
.9-1.1
8
10
34, 35
Spark Ignition
w/o controls
with controls
CVCC (w/o controls)
Diesel (pre-chmaber)
w/o EGR
with EGR
Rankine Cycle
Gas Turbine
Stirling
a - relative to 1976 Emission Standards
b - relative to the conventional gasoline engine
c - numbers refer to list of references (Section 4.0)
d - w/o controls refers to reference 197Z vehicles
e - present designs, advanced versions will have NO emissions closer to 1976 standards
3
3
1
1
25
. Z5
. 7
. 5
1
. 1
6
3.0
4e
8e
. 5
1. 5-Z
1.5-2
2-3
1. 5-Z. 5
1. 5-Z
.65
.65
1. 25-1. 5
1. 0-1. 5
.67
Z7
Z7
40
40
40
Z-59
-------
encountered in urban driving. Reduction of the NOX emissions from the gas
turbine requires significant modifications of the combustor design.
2. 6. 2 Conventional Gasoline Engines
In this section the potential for reducing HC, CO, NOX emissions
from medium duty trucks using the various control systems listed in Table
2. 10 is discussed in detail. Methods are presented for determining the exhaust
emissions from trucks using specified control systems. This can be done
once the baseline emissions from the truck and the following information char-
acterizing the effectiveness of the control system are known:
1. Mean reduction factors.
2. Standard deviation of the reduced emissions when the
system is used on a large number of trucks.
3. Mean deterioration factor between 4, 000 and 50, 000
miles.
Information concerning the effect of the control system on vehicle driveability
and fuel consumption is also needed to assess the influence of the control
system on the truck operation. The information needed to characterize the
control systems is available for light duty vehicles (GVW less than 6,000 Ibs)
but very little is available pertinent to medium duty trucks (GVW between
6, 000 and 14, 000 Ibs). Hence light duty vehicle data must necessarily be used
extensively in characterizing the various control systems used on medium duty
trucks.
The following general approach was taken in adapting the light
duty vehicle results to medium duty trucks. First, the control effectiveness
(fractional reduction in HC, CO, NOX emissions relative to a baseline level)
2-60
-------
of each system when used on standard-sized passenger cars (4500-5000 Ibs)
was determined from emissions data obtained by the automobile industry and
their suppliers during the course of emission control system development and
evaluation programs for LDV. Second, it was assumed that for each system
the same effectiveness could be achieved for MDV applications after the system
had been suitably developed to meet the specific needs/conditions of the truck
applications. Third, when the limited truck chassis dynamometer and engine
emissions mapping data permitted, the reasonableness of the predicted MDV
control system effectiveness factors was assessed. The important topic of the
differences between the control of emissions from light duty and medium duty
vehicles is discussed in considerable length in Section 2. 6. 2. 4-5.
2. 6. 2. 1 Emission System Control Effectiveness Factors
As stated previously, it was assumed that the control effectiveness
information available for passenger cars could be adapted to truck applications
when expressed in terms of a reduction factor. As in the case of the trucks,
the baseline engine/vehicle configuration used for light duty vehicles in the
present study was that of 1972 (outside California). The corresponding base-
•J*
line emissions (gm/mi) are:
HC - 1. 7 ± . 63
CO - 16. 5 ± 6
NOX - 4 ± 1
where the uncertainity is effectively the standard deviation. This means that
the emissions of 68% of the cars fall within the range indicated or that 95%
o- 'Jf
*T* 1"
fall within the average ± 2 IT. The baseline emissions for HC and CO were
obtained from the 1972 light duty vehicle certification results given in Refer-
ence (8), while the NOX baseline emission level was taken from the GM
production audit results listed in Table 2. 13.
* All emissions results given in this report are for the 1975 CVS-CH test
procedure. 1972 CVS-C data are converted to 1975 CVS-CH results as
follows: 1975 HC = 1972 HC/1. 13; 1975 CO = 1972 CO/1. 39; 1975 NO =
1972 NO.
** Based on 25 randomly selected GM, Ford and Chrysler vehicles having
inertia weights of 4000 - 5000 pounds.
2-61
-------
Table 2. 13 Engine Emissions at Low Mileage;
Mean and Standard Deviation
GM 1972 production^
audit
Best GM division
1972 production
Potential' '
best engine emissions,
lean carburetion
(e\
Potential bestv '
engine emissions,
rich carburetion
Emissions in grams/mile
HC CO NQX
mean (S. D. ) mean (S. D.) mean (S. D. )
1.7 (0.64)
1.2 (0.32)
1 (0. 15)
1. 5
22 (8.3)
16 (6.2)
10 (3)
25
4 ( 1)
(c)
4 ( 1)
(c)
2. 5
1. 5
(a)
1972 CVS-C test procedure
^3656 vehicles tested
^'California 7-mode test emissions multiplied by 2
' 'Standard-size car, with quick heat manifold, improved
carburetor, quick acting choke, and EGR
^e'Same as (d) and with air injection injection into the exhaust
manifold
2-62
-------
Reduction factors are determined by dividing the vehicle emissions
obtained with a given control system by the mean baseline value. The reduction
factor R is defined as:
R = X +_ Y
•J*
i-
The quantity X is the mean reduction factor and Y is the uncertainity in the
reduction factor due to the statistical variation in the emissions data. Y can
be considered as a rough approximation of the standard deviation. In many
cases, these was not a sufficient set of data to calculate a true standard
deviation. The emission using the j control system can then be expressed
as:
EM = X (EM)° i = HC, CO, NO
11 x
(SD) J. = Y (EM)!
•where
= mean emission of the i pollutant using system j
(SD) = standard deviation of the emissions for the i pollutant
and j system
It will be assumed that X, Y are the same for trucks and cars independent
of truck weight. (EM)° for the trucks will, of course, vary with weight as
shown in Figures 2.7-9.
In estimating controlled truck emissions, it is also necessary to
estimate deterioration factors for each system. This is difficult to do even
for cars for those systems which have been tested in a large number of vehicles.
Since there are no data available for the durability of control systems used on
medium duty trucks, the deterioration of each system will be rated qualitatively
* The interval about the mean which included all the data except extreme
outliers was determined by scanning a compiled list of typical emissions
data for each control system. Y was then calculated by dividing one-half
that interval by the reference baseline value.
2-63
-------
as low, medium, or high, where each category is defined as follows:
low - 10% or less
medium - 10 - 30%
high - 30% or greater
It is assumed that the assigned deterioration would occur over 50, 000 miles in
the case of mechanical components and 25,000 miles in the case of catalysts.
The effectiveness of each of the control systems considered for
conventional gasoline engines is discussed individually in the following para-
graphs. The components listed for each system are identified and described
briefly in Appendix A-4. The emissions data used to determine the reduction
factor R are referenced and in most cases typical support data are included in
tabular form in Appendix A-5.
System o: EM° (baseline)
The baseline system is that used in most 1972 vehicles outside of
California. It consists entirely of engine modifications such as spark timing,
carburetor A/F ratio, and compression ratio changes. The emissions from
(Q\
this system were determined from the 1972 LDV certification data and the
GM 1972 production audit emissions data given in Table 2. 13. The reduction
factors are:
HC CO NOy
R = 1 + . 375 1 + . 375 1 + .20
Certification data indicate this system has very low deterioration.
System 1; EM° + El + FC + AI + EGR
*
This emission control system is essentially that used on most 1973
passenger cars. Its control effectiveness was determined from the 1973 LDV
(9)
certification data . The reduction factors are:
HC CO NO^
R = 1.35jf.30 l+_.23 .64^.10
This system should show low (less than 10%) deterioration.
* El is not standard equipment on most 1973 LDV but this will not have a
significant effect on low mileage emissions.
2-64
-------
System Z: EM° + El + 1C + QHI + AI + EGR
This control system is essentially that which will likely be used
in LDV in 1975 (outside of California) now that interium standards have been
set by EPA. The control effectiveness for this system has been determined
using the GM and Ford data given in References (10, 11). Sample emissions
data for this system are given in Table A-5. 1.
HC CO NOX
R = . 65 + . 15 . 55 +_ . 15 . 6 -f . 1
This system should show low deterioration.
System 3: EM° + El + 1C + QHI + AI + PC + EGR
This control system is that which was being developed to meet the
original LDV 1975 emissions standards. Using Ford and GM pre-certifica-
tion data (Table A-5. 2), the reduction factors for this system were
found to be:
HC CO NOX
R = . 18 _+ . 05 . 15 + . 03 . 6 -f . 10
The LDV pre-certification data ^ for this system has been analyzed by
EPA^41^ and it was found that the average 50, 000 mile deterioration
factors were 1.5, 1.5, 1.1 for HC, CO, NO emissions respectively.
System 4; EM° + El + 1C + QHI + EGR + AI/CAI + RC + PC
This is the control system being developed to meet the . 4 gm/mi
NOx standard. There is relatively little data available for this system and no
fleet testing has been done. Using the GM data '^' given in Table A-5. 3, the
following reduction factors are estimated:
HC CO NOX
R = .18-f.05 .lSjf.03 . 075 +_ . 05
At the present time, this is a high deterioration system for NOX emissions,
but before it can be put into production this rapid deterioration for NOX would
have to be drastically improved.
System 5; EM° + El + EFIC + EGR + RC/OC
This is the most advanced prototype catalyst system being considered
for gasoline engines and is in a relatively early stage of development. Very
limited emissions data are available for this system but considerable development
2-65
-------
work is currently in progress. A projection of the .limited test results
(Table A-5.4) indicated that the following system effectiveness can be attained:
HC CO NOy
R=.18+.03 .15 + .-25 . 075+_.025
The deterioration of this system depends on both the catalyst and C>2 sensor
durability. Achieving low deterioration for this system will require considerable
development work.
System 6: EM° + El + 1C + QHI + EGR + LTR
This is the system developed by the Ethyl Corporation and is termed
a "Lean Thermal Reactor". It is described in detail in Reference (16). Per-
tinent emissions data for the LTR system are given in Table A-5. 5. The esti-
mated reduction factors are:
HC CO NOy
R=.50+_.07 .35^.05 . 375 +_ . 05
Durability data given in Reference (16) indicates that the deterioration of this
system is low.
System 7: EM° + El + FC + EGR + AI + RTR
This is the thermal reactor system developed by Dupont , Esso, and
(13)
GM and is termed the "Rich Thermal Reactor". Typical emissions data using
this system are given in Table A-5. 6. The estimated reduction factors are:
HC CO NOX
R=.08 + .02 . 35+_.09 . 17 + . 03
This should be a low deterioration system
System 8: EM° + El + FIG + IQHI + AI + EGR
This is a system using advanced carburetion and intake air heating
for which the atomized liquid fuel behaves almost as a gaseous fuel and the need
for choke operation during engine warmup is eliminated. Both Ford and GM
are developing such advanced, non-catalytic low emissions systems. Emissions
data taken from References (10, 11) for this type of system are given in Table
A-5. 7. The estimated (projected) reduction factors are:
2-66
-------
HC CO NOy
R=.40±.07 .30±.05 .35 ± . 05
The projected NOX emissions reduction has been taken essentially equal to that
already achieved by the LTR system. This should be a low deterioration system.
The reduction factor information for all the systems considered is
summarized in Table 2. 14. Note that even though all of these reduction factors
were developed from LDV emissions data, it is assumed that comparable
systems in each case can be developed for truck applications with the stated
control effectiveness and durability. This will undoubtedly require further
development and in some cases new, but similar, components. This topic is
discussed in greater detail in Section 2. 6. 2. 5. 2.
2. 6. 2. 2 The Effect of Control Systems on Fuel Consumption
The effect of each of the emissions control systems on truck fuel
consumption was also investigated. The same sources of data used to estimate
the emission reduction factors were surveyed to estimate the effect of the con-
trol systems on fuel consumption. In general, as indicated in Figure 2. 10, the
fuel penalty associated with the emissions control system increase as the level
of NOX emission is reduced. However, the magnitude of the penalty at a given
NOX value is effected by the control method used to reduce NOX. The various
methods are given below ranked in order of increasing fuel penalty.
1. Reducing catalyst
2. Lean carburetion
3. EGR
4. Rich carburetion
There are two methods which are commonly used to determine the
fuel economy for a given vehicle/engine/control system combination. One
involves actual road testing of the vehicle over a specified driving route and
(19)
the second involves the use of vehicle mass emissions (CO.,, CO) ob-
2-67
-------
Table 2. 14 Summary of Emission Control System Reduction Factors
Reduction Factors
(2)
i
o^
oo
No.
0
1.
2.
3.
4.
5.
6.
7.
8.
EM
,(1)
EM° + El + FC +
AI + EGR
EM° + El + 1C +
QHI + AI + EGR
EM° + El + 1C +
QHI + EGR + AI
+ OC
EM° + El + 1C +
QHI + EGR + RC
+ AI/CAI + OC
EM° + El + EFIC
+ EGR + RC/OC
EM° + El + 1C +
QHI + EGR + LTR
EM° + El + FC +
EGR + AI + RTR
EM° + El + FIC +
IQHI + AI + EGR
HC1_4>
1 ± .375
1.35 ± . 30
. 65 ± . 15
. 18 ± .05
. 18 ± .05
. 18 ± .03
.50 ±.09
.08 ±.02
.40 ±.07
ccf4)
1 ±.375
1.0 ± . 23
. 55 ± . 15
. 15 ± . 03
. 15 ± .03
.15 ±.025
. 35 ± .05
. 35 ± .09
.30 ±.05
1 ± . 20
. 6 ± . 10
. 6 ± . 10
. 6 ± . 10
,075 ±.05
075±.035
.375 ±.05
. 17 ± .03
. 35 ± .05
System
Deterioration
L
L
(3)
M (HC.CO)
L (NO )
x
M (HC.CO)
H (NOX)
H
L
L/M
(1) Baseline engine - 1972 #
(2) System effectiveness at low mileage (£4000 miles)
(3) Deterioration of present systems; L= 10%, M = 10 - 30%, H=30%
(4) All emissions data taken using or corrected to 1975 CVS-CH test procedure
* Based on LDV prototype systems, see pg. 2-63 for explanation.
-------
NOX CHANGED BY VARYING FUEL, EGR AND SECONDARY AIR METERING
(REF. 21)
1.5
1.0
NOx-GM/MI.
(DETERMINED ON
CVS TEST) 0.5
0
0 10 20 30 40
FUEL ECONOMY - % LOSS FROM BASELINE CVS
(REF. 20)
o
O ITR
• IT"
< ITR
a
A
n
cf
0
R.
ft.
R*
R*
in.
IS.
T*.
Tff.
cm
f.»
,„
'*"
C(p
'.R
',*>
r.»
f-»
"Wfl
F-»<
f Mr
[inr
MJ1"1
»tcr
n'.o
f '.'.0
i'C/f/
IM'JM
MrV-.,'H| '.
ros-ufj C
p(/vt'*'. | C
C»fv) C
I [»;'Tjf r S^TtM) N
«w) T
/>w 1 C
•) f*T crwv C
f H VM ' v( H J
'
r
If -f rPf
oi 1IR
J* ">r''r/
9Ht»*t
'f
I ' - StjO
BIB.fCP. HC/CO Cil COWV
|fO«0"«AIIUUU H'OBI" VIM I
[OR . K/CO CAT COW
"MODIFIED M«> (iFo«T'vtH)
X mR.[CRICHR»SLE»)
+ «/COC
-------
tained from a standard chassis dynamometer emissions test. The fuel eco-
nomy experienced with a given vehicle varies significantly depending on the
type of driving (city, suburban, highway, etc. ) of interest. In the present
study, the fuel economy results discussed correspond to city/suburban driving
appropriate to the LA-4 driving cycle. It is assumed that the incremental
effect (fuel penalty) of the control system can be determined equally well
using the road test and chassis dynamometer approaches.
The format for expressing the fuel penalty factor FP is similar
to that used for the reduction factors R - namely:
(FP). = A. ±a.
J J J
tVi
where A. = average fuel penalty {%) using the j system
a- = scatter of the fuel penalty data (%) for the
.th
j system.
"a" is essentially the S. D. of the fuel economy data (MPG). As in the case of
emissions, the baseline for fuel economy was taken to be 1972 model trucks.
o
The baseline fuel economy Fe (miles per gallon on the LA-4 driving cycle)
was calculated from the (CO7,CO) emission data for 1972-73 trucks given
(19) ° .
in Reference (18) using the following relationship between Fe, (CO } , (CO)
F°e = 236°
.429 (CO) + . 272CC02)
o
where Fe^MPG;(COj, (CO2)~gm/mi
o
As shown in Figure 2. 11, Fe is a function of both vehicle inertia weight and
engine CID. The fuel economy for a given vehicle/engine/control system
combination can be expressed as:
Fe = Fe/1 + FP
2-70
-------
13
tSJ
1
Iw - INERTIA WT, K-LB
Figure 2.11 BASELINE FUEL ECONOMY (MPG) FOR MEDIUM DUTY VEHICLES
-------
Fuel penalty information for the various control systems con-
sidered is summarized in Table 2.15. Indicated in the table are the sources
of the data used to estimate the fuel penalty for each system. Typical data
are given in Appendix A6. As in the case of emissions reduction factors
R, it is assumed that the fuel penalty factor FP determined using LDV data
is also applicable for trucks independent of inertia weight.
2. 6. 2. 3 Effect of Emissions Control on Truck
Driveability and Engine Selection
In addition to the fuel penalty which was discussed in the previous
section, the use of emissions control systems on conventional gasoline
engines can lead to other undesireable side-effects on vehicle operation.
These other side effects which are often grouped together and called drive-
ability problems include surge and hestitation during acceleration, rough
idle or stall when the engine is cold, and reduced vehicle performance (ex.
rate of acceleration or maximum speed). The major source of these drive-
ability problems is the control means taken to reduce the NOX emissions.
These include EGR , retarded timing, and very lean carbureter A/F ratios.
The result is less efficient and rougher combustion especially at high engine
RPM. These effects are shown in Figure 2. 12 which was taken from Reference (21).
Note that the average peak pressure is reduced by about 15% using 10% EGR
and that the cycle-to-cycle torque variation increases significantly with both
% EGR and leaner A /F ratios. Hence in order to maintain a desired engine
smoothness and response it becomes necessary to operate at richer carbu-
reter settings when EGR is used. This results in reduced fuel economy.
Driveability problems associated with cold engine operation are less basic
and are presently being minimized using quick heat air induction systems
and programmed spark advance. It can be expected that driveability problems
due to the use of EGR will decrease as more sophisticated carbureters are
developed.
The effect of EGR and the other means of controlling NO.X emis-
2-72
-------
Table 2. 15 Summary of Emission Control System
Fuel Penalty Factors
No.
0
1.
2.
3.
4.
5.
6.
7.
8.
EM'
System
,(1)
Fuel Penalty
Factor (2)(%)
Sources/Tables
(3)
EM° + El + FC
+ AI + EGR
EM° + El + 1C + QHI
+ AI + EGR
EM° + El + 1C + QHI
+ EGR + AI + OC
EM° + El + 1C + EGR
+ RC + AI/CAI + OC
EM° + El + EFIC +
EGR + RC/OC
EM° + El + 1C + QHI
+ EGR + LTR
EM° + El + FC + EGR
+ AI + RTR
EM° + El + FIC + IQHI
+ AI + EGR
7
5
8
12
3
8
25
3
± 3
± 2
± 2
± 2
± 2
± 2
± 5
± 2
Reference (9)
Reference (10, 11, 13)
Reference (10, 11), Table A6. 1
Reference (2)
Reference (15)
Reference (16), Table A6. 2
Reference (13), Table A5. 6
Reference (10, 11)
(1) Baseline engine - 1972 (baseline fuel economy)
(2) Fuel penalty in urban driving (LA-4 driving cycle)
(3) Tables found in Appendixes A5.A6.
2-73
-------
ENGINE SPEED: 2000 RPM - BRAKE MEAN EFFECTIVE PRESSURE: 42.7 PSI - IGNITION TIMING: 40° BTDC
Pmax-pSI
427
356
284
214
A.
A..
I
W/0 EGR
\
\
10%
° 15%
A 20%
I I
12 14 16 18
A/F RATIO
CRANK ANGLE AT
PmaxATDC-DEG'
12 14 16 18
A/F RATIO
CRANK ANGLE AT
28
26
24
22
20
18
16
14
_
15% EGR
0
/
o
0/ W/O EGR
/ o*"~°
o o
- /
y
./
i i i i
28
26
24
22
20
18
16
14
(REF. 21)
A/F = 13.0
I
I
I I
0 5 10 15 20
EGR RATIO
ENGINE SPEED: 2000 RPM - TORQUE: 26 FT.-LB. - IGNITION TIMING: 40° BTDC
16
14
12
TORQUE
VARIATION 10
RATE
% 8
6
4
2
0
11
12
15% 10%
EGR EGR
5% WITHOUT
EGR
EGR
I
I
13
14 15
A/F RATIO
16
17
18
Figure 2.12 EFFECT OF EGR ON CYLINDER COMBUSTION PARAMETERS
2-74
-------
sions on driveability will likely be more serious for trucks than LDV because
the lower power-to-weight ratio of trucks and their driveline characteristics
(gear and axle ratios) result in engine operation at high loads and engine
RPM a greater fraction of the time. Hence a reduction in maximum horse-
power and the occurrence of rough combustion at high RPM are more notice-
able in MDV than in light duty vehicles. As a result it is likely that larger
engines will be used in trucks than in the past and that it will be more dif-
ficult to attain the desired emissions reductions and at the same time main-
tain good vehicle driveability.
2.6.2.4 Emission Control System Characteristics
(Data) for Medium Duty Tr.ucks
As noted previously, the emission reduction and fuel penalty
factors defined in the two previous sections were evaluated using light duty
vehicle data. This was unavoidable because only very limited medium duty
data were available. In this section, the available MDV data are summarized
and their compatibility with the emissions reduction and fuel penalty factor
predictions assessed.
Emission control system data pertinent to MDV with gasoline
/ 1 Q\
engines are available from two sources. EPA/Ann Arbor tested two
trucks which were retrofitted with EGR and an oxidizing catalyst; Southwest
Research Institute (SWRlr has performed a series of engine dynamometer
tests on two V-8, heavy duty, gasoline engines fitted with various control
systems including EGR, air injection, and an oxidizing catalyst. These two
sets of data are summarized in Tables 2.16-17 for comparison with the pre-
viously determined emission reduction and fuel penalty factors.
In Table 2.16, composite emissions data for HC, CO, NOX are
shown for the pick-up truck and the stake truck tested at inertia weights
between 5500 and 7000 Ibs. Also shown are data for a light duty Ford F-100
truck having a 1975 prototype emissions control system tested at 4500 Ibs.
2-75
-------
TABLE 2.16
SUMMARY OF MEDIUM DUTY TRUCK EMISSION
CONTROL SYSTEM EFFECTIVENESS DATA
Fuel
Truck
Inertia
Weight
Control
System
Pick-up(1972) 5500 none
Pick-up(1972) 5500 EGR+OC(1)
Pick-up(1972) 6500 none
Pick-up(1972) 6500 EGR+OC^
Stake(1972) 7000 none
Stake(1972) 7000 EGR+OC*2)
F-100(1975)(3) 4500 EGR+OC+AJ
(1) 60 in volume, retrofit
(2) 180 in volume, retrofit
(3) 1975 prototype Ford System
(4) Reduction factors calculated from
(5) All emissions in gm/mi using 1975
Data
Source
EPA
EPA
EPA
EPA
EPA
EPA
EPA
baseline
CVS-CH
HC<5) RHC
3.23
. 35 . 108
2.92
.50 .171
7.99
1.20 .15
.20 .117®
emissions (1972
test procedure
co'5' Rco
44
3.29 .075
39.6
7.. 25 .181
81.9
10.99 .134
1.39 .085
LDV)
NO*5'
X
6.43
2.91
6.58
4. 02
7.49
4.16
2. 56
Penalty
NO MPG FP(%)
11.2
.454 10.25 9.0
10.0
.625 8.85 I3-0
10.2
.55 8.7 17
.63 10.8 10
-------
TABLE 2. 17
SUMMARY OF ENGINE DYNAMOMETER EMISSION
CONTROL SYSTEM EFFECTIVENESS DATA
Engine
Emissions (gm/bhp-hr)
. . Control
Source System
HC.
R
HC CO
R
CO NO
bsfc Fuel
Ib/hp- Penalty
NO hr FP(%)
r\>
i
V-8, 350 CID
V-8, 350 CID
V-8, 361 CID
V-8, 361 CID
(2)
SWRI none
8.82
31.4
10.85
SWRI none
13.0
35.4
11.00
. 620
SWRI EGR+OC+AI 2.22 .25 18.6 .59 6.23 .58 .667 7.5
.733
SWRI EGR+OC+AI 1.31 .104 19.2 .54 4.09 -39 .831 11.2
(1) Data taken from Reference (22)
(2) 350 CID engine designated as 2-3 in Reference (22)
(3) 361 CID engine designated as 1-3 in Reference (22)
-------
For each truck, the emission reduction and penalty factors are shown in the
table. It is encouraging that in most instances the factors fall within the
ranges given in Tables 2.14. It is also of interest to compare the composite
emissions and bag data for the retrofitted trucks tested at .EPA and the cor-
responding emissions data for the light duty truck equipped with the 1975
prototype control system. Such data are shown in Table 2. 18. Note that in
general the trends of the emissions from bag-to-bag are very similar for
the retrofitted medium duty trucks and the "factory equipped" light duty
truck indicating that the behavior of the catalyst in cold as compared to hot
starts and hot transient operation is essentially unchanged over the weight
range. This again offers encouragement that the reduction factors obtained
from LDV data are applicable for medium duty vehicles. It also shows for
MDV as for LDV the dominance of the engine warmup HC and CO emissions
on the composite vehicle emissions for the 1975 CVS-CH test procedure.
(22)
The engine dynamometer emissions data from SWRI are
summarized in Table 2.17. The engines were tested using the 23-mode cycle
with the composite cycle emissions given in terms of gm/bhp-hr. The ef-
fective emissions reduction factors for each pollutant were determined by
dividing the controlled and uncontrolled composite cycle emissions values.
The reduction factors for the HC and NOX are in reasonable agreement with
those given in Table 2.14, but the reduction in CO emissions is much smaller
than would be expected with the use of a catalytic reactor.
Fuel penalty factor results are also shown in Tables 2. 16-17.
As in the case of the reduction factors, the fuel penalty results from the
truck tests are in reasonable agreement with the values obtained from LDV
data.
2.6.2.5 Differences Between Controlling Emissions
from Light Duty and Medium- Duty Vehicles
The preceding considerations of reducing emissions from medium
2-78
-------
BAG EMISSIONS DATAX
TABLE 2.18
FROM LIGHT DUTY AND MEDIUM DUTY VEHICLES
Vehicle
1973 Chev(Z)
1975 Chev
1975 Plym
1975 Buick
1975 F-100
1972 Stake truck
1972 Stake truck
1972 Stake truck
1972 Stake truck
1972 Stake truck
1972 Chev Pickup
1972 Chev Pickup
1972 Chev Pickup
1972 Chev Pickup
(1) Low mileage;
Inertia Control
Weight System
4500 System 1
4500 System 3
4500 System 3
4500 System 3
4500 System 3
5500 EGR + OC(3)
6000 EGR + OC(3)
6500 EGR + OC*3'
7000 EGR + OC*3)
7000 None
5500 None
5500 EGR + OC<4)
(4)
6500 EGR + OC*
6500 None
Composite
Emissions (gm/mi)
HC
2.75
.38
.38
.34
.20
.97
1. 13
1.11
1.2
7.7
3.3
. 34
.51
3.0
Date received from EPA
CO
24. 1
1.86
4. 11
2.27
1.39
7.75
11.0
11.5
11.7
82.0
47.o
2.9
7.2
41.0
NO
X
2.7
2.2
2.80
1.47
2.56
3.5
4.5
4.36
4. 1
7.6
6.0
2.9
.4.0
6.7
Bag #1
Bag #3
Bag #2
Emission (gm/mi)
HC
3.6
1.00
1.39
.87
. 35
2.2
2.69
2.66
2.90
8.6
4. 3
.82
1.20
6.7
(2) This data taken at Calspan
CO NO
X
30.0 3.25
7.53 3.26
16.2 3.19
9.08 2.08
7.47 2.82
25.0 4.0
29.0 5.1
35.0 5.3
35.0 4.8
88.0 8.6
62.0 7.2
11.5 3.86
2.3 4.85
5.7 7.87
HC
2.9
.38
. 15
.23
.33
.66
.85
.72
.80
6.8
2.8
.25
.46
3.0
(3) Retrofit; OC Vol
(4) Retrofit; OC Vol
CO
27.6
1.93
1.80
.90
.65
5.4
8.6
8.84
9.1
75.0
29.0
1.2
-
3.3
= 60 in3
= 180 in*
NO
X
3.07
2.49
3.0
1.47
3.02
4.6
5.8
6.25
5.2
8.54
7.6
3.72
-
8.5
HC
2.65
. 15
. 10
.09
. 10
.645
.68
.70
.69
7.8
3.2
.19
.25
2.9
CO NO
X
22.3 1.96
.09 1.66
.57 2.54
.30 1.23
.16 2.21
. 2.06 2.76
5.0 3.8
5.55 2.94
3. 50 3. 20
82.0 7.5
52.0 4.6
. 38 2. 09
.76 2.67
39. 5.2
-------
duty trucks have rested heavily on experience and data from control systems
on light duty vehicles. There are, however, differences in controlling emis-
sions from vehicles in the two weight classes which should be considered.
These differences are mainly due to the fact that the power-to-weight ratio of
light duty vehicles does not change significantly with weight. For medium duty
trucks, however, the power-to-weight ratio tends to decrease as the GVW
increases. This occurs for the most part because the same size (CID) engines
are used in both standard-sized cars and medium duty trucks. When the en-
gine is used in a MDV, it operates at a higher load which on the average results
in higher emissions with increasing vehicle weight (see Figures 2. 7-9). As shown
by the pre-control surveillance data for LDV given in Reference (39), this is
not the case for LDV except for NO emissions since the emissions levels found
r x
for HC and CO did not vary systematically with vehicle weight up to 5500 pounds.
An analytical method for estimating the increase in baseline emissions with
weight for MDV has been developed. The method is described in some detail in
Appendix A7 with only the basic approach and numerical results being given in
the main body of the report (Section 2. 6. 2. 5. 1). The effect of the increased
engine load on the design and operation of the various control systems is then
discussed qualitatively in Section 2. 6. 2. 5. 2.
2.6.2.5.1 Incremental Effect of Vehicle Weight
on Baseline Emissions
As shown in Figures 2.7-9, the baseline emissions of MDV increase
with vehicle inertia weight. This increase in emissions is usually attributed
to the higher engine HP required to propel the heavier vehicle. A simple
analytical method was developed to predict the effect of vehicle weight on
emissions (gm/hr) as a function of load (HP) and engine RPM, vehicle char-
acteristics (weight, frontal area, drag coefficient, rolling resistance, axle
ratio, etc. ), and driving cycle (average speed, percent time in acceleration
and cruise, etc. ). The method, which does not attempt to account for the
effect of cold starts or driving transients, is described in Appendix A7. It is
assumed that most of the incremental emissions beyond that for a standard
2-80
-------
size LDV with the same engine are due to the increased horsepower required
to accelerate the vehicle and to maintain cruise velocity. Hence only the
incremental and not the baseline LDV emissions are calculated.
Four vehicle classes are considered in the analysis - pick-up
truck, van, stop-van, and passenger car. For each vehicle class, the
mean horsepower required in acceleration and cruise driving modes is cal-
culated from the following equation.
(HP) road = -i- .0668 WV ^- + .0039 CD AF ~V3~~
dt
+ V W (K + K2 V)
where
W = Vehicle weight (Ibs)
C , A = Drag coeeficient and front area (ft ) of the vehicle
V = Speed (mph)
d V
—-— = Acceleration (mph/sec)
——3— = Average of the velocity cubed
K^ , K£ = Constants in the rolling resistance equation
The constants associated with each class of vehicles are given below.
Vehicle
Pick-up Truck
Van
Stop-Van
Passenger Car
CD
.5
.65
.65
.45
AF (ft2)
29
34
44
21
Kl
. 015
. 015
. 014
. 017
K2
. 00026
. 00026
. 00022
. 000334
In order to caluculate the mean horsepower in the acceleration
and cruise modes appropriate to the LA-4 driving cycles, one requires values
for the following quantities.
V = average velocity in the mode
d V = average acceleration in the mode
dt
2-81
-------
V = average of the velocity cubed in the mode
Such information is conveniently summarized in ref (23). In the present
work, the 5-city composite results were used as they compare closest with
the LA-4 cycle. Distribution of total time in mode, acceleration, and velocity
mode data are given in Appendix A7. The driving cycle inputs needed to
calculate the mean horsepower and incremental emissions are summarized
in Table 2.19.
Eq. (I) was evaluated for the four vehicle classes and a range of vehicle
weight. The results are shown in Table 2. 20. As expected the required mean
horsepower for both acceleration and cruise modes increases with vehicle
weight. The engine RPM for the two operating modes of interest were also
determined. It was found that
Eng. RPM
Mode Velocity Car Truck
Acceleration 26 1450 1970
Cruise 37 1300 1770
Now one can proceed to calculate the incremental emissions from the engine
emission mapping data.
It was assumed that all the vehicles were powered by a V-8,
350 CID engine. Engine dynamometer emissions data for that engine are
given in Reference (22) (designated as 2-3 in that report). Unfortunately, the
test cycle included only 1200 and 2300 RPM as shown in Figures A-7. 2-4. Inter-
mediate RPM were faired in following the general shape of two bounding data
curves. The general approach taken was to calculate the difference between
the emissions from a truck of weight I and a reference passenger car of
weight 4500 having the same engine. The average emissions from the re-
ference passenger car for the LA-4 driving cycle are well know from emis-
sions tests. It is assumed that the trucks are tested on the same LA-4 driving
cycle. Hence the total cycle time is 23 minutes and the length of the. route is
7. 5 miles. Now the incremental emissions from a truck can be written as
2-82
-------
TABLE 2. 19
URBAN DRIVING CYCLE CHARACTERIZATION
Total Time in Mode
Mode
Idle
Cruise
Acceleration
Deceleration
5-City
Composite
12.9
31.8
29.1
26.2
N.Y.C.
17.5
26. 5
29. 1
27.0
LA-4
13.6
27. 3
31.7
27. 5
Average Velocity Average Acceleration _
V (mph) dv/dt (mph/sec) V
Acceleration
Cruise
26
37
.8
0
25,000
76,700
(1) Data obtained from Ref (23)
(2) Average conditions are for the 5-city composite
2-83
-------
TABLE .2.20
ROAD AND ENGINE HORSEPOWERS
FOR ACCELERATION AND CRUISE MODES
Acceleration Mode
Cruise Mode
W Pick-Up
4500 18.6
(24.8)
6000 23.9
(31.9)
8000 31.0
(41.2)
10000 38.1
(50.5)
12000 45.2
(60.2)
52. 3
(69.5)
HP
Van
19.9
(26. 5)
25.2
(33.4)
32.4
(43.0)
39.5
(52.5)
46.6
(61.8)
53.7
(71.5)
Stop- Van
20.6
(27.2)
25.8
(34.2)
32.7
(43.4)
39.7
(52.7)
46.6
(61.8)
53.5
(71)
Pick-Up
15. 3
(16.9)
17.8
(19.8)
21. 1
(23.4)
24.5
(27.2)
27.8
(30.8)
31.0
(34.4)
HP
Van
19.5
(21.6)
22
(24.4)
25. 3
(26.0)
28.6
(31.7)
31.9
(34.4)
35.2
(39.2)
Stop-Van
22. 3
(24.8)
24. 5
(27.3)
27. 5
(30.5)
30.4
(33.6)
33.4
(37.2)
36.4
(40. 5)
Top number = road horsepower
Bottom number ~ engine horsepower
Values for 4500 passenger car
Acceleration Mode
18.5
(24.7)
Cruise Mode
14.0
(15.5)
2-84
-------
. / gmE ) ~|
V h*7450° I
carl
E (gm/mi) =[/gmE ] _ / gm E | / 23
'truck " \ hr /4500 [ 60 (% time in mode
7.5 mi
E = HC, CO, NO (2)
.X
Equation (2) is applied for both the acceleration and the cruise mode.
GmE/hr are obtained from Figures A-7. 2-4 using the appropriate values of HP
and engine RPM. Table A-7. 2 shows a typical set of calculations for the van-
truck.
The computed emissions results are compared with the medium
duty truck baseline correlations as a function of inertia weight in Figure 2. 13.
In the case of HC and NO the prediction procedure does reasonably well in
.X
accounting for the effect of vehicle weight and in giving a reasonable estimate
of the initial value at I. = 4500 Ibs. In the case of CO, however, both the
trend with weight and the initial value are much less than was found exper-
imentally. These large discrepancies are probably due to the importance
of the cold start and the fact that the mean horsepower approach does not
account for time spent near rated horsepower where the specific emissions
(gm/bhp-hr) are very high. As might be expected the averaging approach
works best for NO emissions which vary smoothly with HP.
x
2.6.2.5.2 Differences in the design and operation
of Emissions Control Systems in Trucks
and Cars.
As noted previously a key assumption in the present study wac
that the same emission reduction effectiveness could be achieved with a given
control system in a medium duty truck as in a light duty vehicle. In addition,
satisfactory system durability and vehicle driveability are required in the
truck. There are, however, several reasons why it might prove to be dif-
ficult to attain these goals for certain truck/engine/control system combina-
tions. These differences between the design and operation of emissions con-
trol systems in medium duty trucks and passenger cars are considered in this
section.
2-85
-------
!„ INERTIA WT. K LB
*• <
VAN-TRUCK
V-8, 350 CID
8 60
PflEDICTEO INITIAL VALUE - 8.6 jm/ml
I^NCRTIA WT. K4.B
• a
l^-INERTIA WT. K-L8
Figure 2.13 COMPARISON OF PREDICTED AND MEASURED EMISSIONS AS A FUNCTION
OF VEHICLE INERTIA WEIGHT
2-86
-------
As discussed in the previous section, it is common practice for
many MDV to operate at much lower power-to-weight ratios than for passenger
cars. Hence when used in a truck an engine operates at a greater fraction of
its rated horsepower than in a car. The increase in engine load (HP) was
calculated as a function of vehicle weight and shape in the previous section.
In addition, at a given vehicle speed, the engine RPM is higher for a truck
than a passenger car because the axle ratio used in trucks is considerably
higher. The higher axle ratio is needed to partially compensate for the lower
power-to-weight ratio. Hence, in general, a given engine operates at a higher
load (HP) and higher speed (RPM) when it is used in a truck than in a car. These
differences in engine operating conditions can have important consequences in
applying the various control systems to medium duty trucks.
Consider first the effect of higher engine RPM. This could make
it more difficult to maintain acceptable driveability when using EGR, retarded
spark timing, and lean carburetor settings to reduce NO and lead to the use
.X
of larger engines (greater CID) in medium duty trucks than is the current
practice. Acceptable driveability could also be maintained by using richer
carburetion but this would result in an additional fuel penalty. Both of these
approaches to solving the driveability problem would lead to higher operating
costs. Improved fuel systems (carbureters, fuel injection, etc.) and more
sophisticated control of proportional EGR systems hopsfully will minimize
driveability problem in trucks with reduced NO emissions and not require
either of the above remedies.
Engines in trucks also operate at higher horsepower than those in
care for a given type of driving. This can have important consequences relative
to the durability of catalytic converters, because it results in higher pollutant
flow rates and exhaust gas temperatures than would be experienced in a light
duty vehicle. The higher heat load to the catalytic converter would occur
both during part-to-full throttle and motoring (deceleration) modes of engine
operation. It is likely that the higher catalyst operating temperature will at
least compensate for the reduced gas residence time and, as a result, the
2-87
-------
conversion efficiency of the converter in the MDV will be at least as high as
in a LDV. However, it can be expected that to attain the required system dura-
bility and to optimize the conversion, efficiency (achieve minimum emissions)
(24)
considerable development work beyond that done for LDV will be necessary.
In that work, various combinations of converter volume, location, catalyst
loading, and cross-sectional flow area would be tested. In addition, more
elaborate catalyst protection schemes than those found necessary for LDV will
probably be needed for MDV because in the latter case the catalysts will operate
at a higher average temperature.
2. 6. 3 Alternative Engines
The exhaust emissions from medium duty trucks can be reduced
by replacing the conventional gasoline engine by an alternative engine having
lower baseline emissions. As indicated in Table 2. 12, a number of such
power plants are being developed which can be considered for future use in
MDV. At the present time, none of these alternative engines is developed to
the point that mass production is possible within the next several year even
though several of them are attractive possibilities to at least share the MDV
engine market with the conventional gasoline engine within ten years. The
most promising of the alternative engines are the light weight diesel and the
three-valve carbureted pre-chamber (CVCC) engine. Development work on
both of these engines is proceeding rapidly at the present time and it appears
likely they could be in limited production in 5 or 6 years. The emissions and
fuel consumption characteristics of these engines are discussed in the following
sections.
2. 6. 3. 1 Diesel Engines
At the present time diesel engines are used in the majority of
heavy trucks (GVW>20,000 Ibs) because they have better durability, lower
2-88
-------
maintanence costs, and superior fuel economy than the conventional gasoline
engine. Diesel engines are, however, significantly heavier, larger, and
initially more costly than the comparable gasoline engine of the same horse-
power. It is these latter disadvantages which have precluded the extensive
use of the diesel engine in medium duty trucks at the present time. Work is
presently underway, mostly in Europe and Japan, to develop a light weight
diesel engine that would be suitable for both light duty and medium duty truck
applications. The approach being taken is to tradeoff some of the extreme
durability (up to 500, 000 miles before overhaul) for reductions in weight,
size, and inital cost. In all probability, the advanced light weight diesel would
be turbo charged and be of the pre-chamber design. It would still be
slightly (25%) heavier and larger than the comparable gasoline engine, but
would have significantly lower baseline emissions and fuel consumption. It
is assumed in the present study that the emission and fuel consumption char-
acteristics of the light weight diesel will be comparable to those of the present
heavy duty versions of the same type (example, turbocharged pre-chamber or
naturally aspirated direct injection). Considerable data are available for the
heavy duty diesel engines presently being used on heavy duty trucks.
2.6.3. 1. 1 Emissions and Fuel Consumption
Characteristics of Diesel Engines
Most of the emissions data pertinent to diesel enigneshave been
obtained on the engine dynamometer because for heavy duty vehicles, the
emissions standards are set for the engine alone rather than for the vehicle/
engine combinationas in the case of light duty vehicles. The only chassis
dynamometer (LA-4) emissions data (gm/mi) available for a vehicle using a
diesel engine is that given in Reference (25) for the Mercedes 220 D which uses
a 4-cylinder, naturally aspirated, pre-chamber engine. As expected the
emissions levels for that vehicle with the diesel engine were much lower than
the corresponding emissions for the vehicle with a gasoline engine, but no
2-89
-------
direct use was made of those data in the present program because of the size
and type of the diesel engine used. Hence in the present work engine dynamo-
meter emissions data are used and a method developed to convert them to driving
cycle emissions (gm/mi) for a truck of specified weight and shape.
Engine dynamometer emissions data for diesels of various types
are summarized in References (26, 27). The engines were tested using several
test cycles (7, 9, 13, 23 - mode test procedures). All the data used herein were
obtained using either the 13 or 23 - mode test procedures which were found in
Reference (28) to yield equivalent results. The composite cycle emissions data
are reported (26,27) as gm/bhp-hr while the specific mass emissions for each
steady-state mode are given as gm/hr for specified load (HP) and engine RPM.
Composite cycle emissions data for uncontrolled diesel and gasoline engines
are summarized in Table 2.21 using results reported in References (22,26-28).
Average baseline values for the HC, CO, NOX emissions from a conventional
gasoline engine, a turbocharged direct injection diesel and a turbocharged pre-
chamber diesel are given at the bottom of Table 2. 21 in terms of gm/bhp-hr.
It is clear that the baseline HC and CO emissions for the diesel engines are
much lower than for the gasoline engine. It is also of interest to note that the
baseline NOX emissions from the pre-chamber diesel are also significantly
lower than for the gasoline engine.
In order to compare the diesel emissions with those previously
estimated for the gasoline engine with and without emission controls, it .is
necessary to convert engine dynamometer emissions results (gm/bhp-hr) to
driving cycle results (gm/mi). This can be done in an approximate manner by
defining an average horsepower HP and average velocity V for the driving
cycle. Then one can write;
Emissions (gm/mi) = (C. F. ) Emissions (gm/bhp-hr)
where C. F. = ~HP/V
2-90
-------
TABLE 2. 21
ENGINE EMISSIONS CHARACTERISTICS
Emissions - gm/bhp-hr
(1)
Fuel
Consumption
Engine
(2)
gasoline-22
gasoline-23
gasoline-2-3
gasoline- 1-3
Diesel-16 p
'i'
Diesel- 18
Diesel-19
Diesel-A
Diesel-B
*
Diesel-G
-,-
Diesel-H'
Diesel-I p
Source
B/M
B/M
(28)
(28)
SWRI<22>
(77\
swRr~~;
B/M
B/M
B/M
B/M
B/M
B/M
B/M
B/M
(28)
(28)
\ *-^ /
(28)
(26)
(26)
(26)
(26)
\ *-* *-* /
(26)
HC
7.
8.
8.
13.
2.
3.
1.
3.
3.
2.
•
67
30
73
34
28
34
26
9
1
1
6
3
Average
gasoline
Dies el- Df
V
Diesel-IDI p
(1) 13/23 -
(2) engine
8
2.
•
68
29
CO
33
41
29
32
1
3
5
10
4
3
4
2
.4
.6
.6
. 3
. H
.74
.21
.0
.2
.9
. 9
. 3
NO
9.
9.
10.
11.
4.
12.
7.
8.
6.
17.
11.
6.
X
6
6
3
7
8
6
7
7
7
8
7
1
Ib/bhp-hr
. 649
. 575
. 631
. 733
. 432
.421
. 502
_
„
„
-
-
Values
37
4
1
.5
. 11
.71
9.
13.
5.
6
8
5
. 647
.421
. 432
• mode test procedure
designation in source reference
* turbocharged
p pre-chamber
B/M Bureau
of Mines; SWRI
- Southwest
Research
Institute
( ) reference
2-91
-------
can be used as the conversion factor between the two sets of emissions data.
The average horsepower can be calculated using the engine load results of
Appendix A-7 and the driving mode data of Table 2. 19 in the relation:
HP = . 318 (HP) cruise + .291 (HP) acceleration
The balance (£40%) of the driving time is spent in idle and deceleration modes
which are assumed to be accounted for in the original averaging of-the 13-mode
engine cycle data. V was taken to be 26 mph. The conversion factor C. F.
calculated as a function of vehicle inertia weight for pick-up trucks and stop-
vans is shown in Figure 2. 14. Using C. F. and the average engine emissions
data at the bottom of Table 2. 21, driving cycle emissions (gm/mi) for HC,
CO, NO were calculated and the results are shown in Figures 2. 15-17 for
2£
medium duty trucks. Figures 2. 15-17 show both the effect of weight on emis-
sions and the large reduction in baseline HC and CO emissions which could be
achieved by replacing the conventional gasoline engine with the turbocharged,
pre-chamber diesel. The absolute magnitude of the predicted gasoline engine
emissions are in reasonable, but certainly not exact, agreement with the ex-
perimental results for MDV given in Figures 2.7-9. Hence in estimating base-
line emissions^results of Figures 2.7-9 are ratioed by the appropriate factor
obtained by dividing the predicted emissions for the different engines types
given in Figures 2. 15-17. Estimated baseline emissions for diesel engine-
powered MDV are given in Figure 2. 18.
The baseline CO and HC emissions for the turbocharged, pre-
chamber diesel are sufficiently low that is is reasonable to assert that it will
not be necessary to reduce them further. Hence the only emission control con-
sidered for the diesel was a further reduction of NOX. As shown by the data
given in Table 2. 22, NOX emissions can be reduced in the diesel engine using
EGR just as they can in the gasoline engine. Note also that the fuel penalty
for using EGR in the diesel engine is smaller than in the gasoline engine. For
2-92
-------
STOP VAN
PICKUP
0.5
8 10 12
Iw - INERTIA WT, K-LB
Figure 2.14 CONVERSION FACTOR BETWEEN ENGINE AND VEHICLE EMISSIONS
2-93
-------
10
O)
o"
TURBOCHARGED
-P-TURBOCHARGED
8 10 12
Iw - INERTIA WT, K-LB
14
16
Figure 2.15 COMPARISON OF DIESEL AND GASOLINE ENGINE HC EMISSIONS
FOR MEDIUM DUTY TRUCKS
2-94
-------
E
o>
o"
O
STOP VAN
PICKUP
GASOLINE ENG NE V-8
DIESEL-DI -TURBOCHARGED
8 10 12
-INERTIA WT, K-LB
Figure 2.16 COMPARISON OF DIESEL AND GASOLINE CO EMISSIONS FOR MEDIUM
DUTY TRUCKS
2-95
-------
20
15
I
STOP VAN
PICKUP
DIESEL-DI-TURBOCHARGEDX.
- DIESEL-IDIP-TURBOCHARGED
8 10 12
Iw -INERTIA WT, K-LB
14
16
Figure 2.17 COMPARISON OF DIESEL AND GASOLINE ENGINE NO.. EMISSIONS FOR
MEDIUM DUTY TRUCKS
2-96
-------
DI DIESEL-TURBOCHARGED
IDI DIESEL - TURBOCHARGED
i
vO
-J
I - INERTIA WT, K-LB
W
Figure 2.18 BASELINE DIESEL EMISSIONS (gm/mi)
-------
TABLE 2.22
SUMMARY OF EMISSIONS FROM DIESEL ENGINES
EQUIPPED WITH NO CONTROL SYSTEMS
x
(2)
Emissions Data
Engine
IDI-P-turboch
IDI-P-turboch
IDI-P-turboch
DI
DI
DI
Control
System
none
5° injection adv,
10% EGR
5 injection adv,
10% EGR,
inter cooling
none
10% EGR
15% EGR .
gm/bhp-hr
HC
. 26
. 29
.64
4.41
4. 12
3.79
CO
1.
1.
1.
5.
5.
6.
09
58
68
93
68
05
NO
X
4.
2.
2,
7.
5.
5.
93
78
44
41
95
30
Peak
Smoke (%)
6.
10
6.
12.
10.
10.
9
5
5
1
1
Ib/bhp-hr
bsfc
.422
.443
.430
. 504
. 510
. 520
Emission Reduction and Fuel Penalty Factors
Engine
IDI-P-turboch
DI
Control
System
10% EGR
10% EGR,
inter cooling
10% EGR
Re due tion_F actors (R
HC
1. 1
2.4
.93
CO
1.45
1.54
.96
N0x
. 562
.495
.80
)
(FP)
Fuel Penalty Factor
1.04
1.02
1.01
(1) Data from Ref (27)
(2) 13/23 - mode test procedure
2-98
-------
a turbocharged, pre-chamber diesel, the appropriate emission reduction and
fuel penalty factors are:
RNOX='57' FP=4%
Fuel consumption data (bsfc) for the gasoline and diesel engines
are also given in Table Z. Zl. Note that the fuel consumption of the diesel
engine is significantly less (about 35%) than that for the gasoline engine. Hence,
the estimated baseline fuel consumption of the diesel engine is given by:
(Fe°) _ (bsfc) diesel _'
diesel (bsfc) gasoline gasoline
o
(Fe) gasoline was given previously as a function of vehicle weight in Figure
Z. 11.
2. 6. 3. 1. Z Odor and Particulate Emissions
from Diesel Engines
In discussing the exhaust emissions from diesel engines, it is
necessary to consider the odor and particulate (smoke) emissions in addition
to the gaseous HC, CO, NO emissions. It is clear from the previous section
that as far as the gaseous emissions are concerned, the diesel engine is an
attractive power plant. Unfortunately part of this attractiveness is reduced
by possible difficulties associated with odor and particulate emissions which
are peculiar to the diesel. Less information is available concerning these
latter diesel pollutants than for HC, CO, NO . The smoke and odor pollutants
5C
are easily perceived by the public even at quite low concentrations, so their
control is critical for public acceptance of diesels for light and medium duty
truck applications. It was concluded from the SWRI emissions tests of
the Mercedes ZZO D that the odor and smoke emissions of that vehicle were
objectionable and needed to be reduced.
Z-99
-------
Reducing the odor of the exhaust gases from the diesel is not a
simple problem as it is even difficult to identify, let alone measure the concen-
tration of, the odor causing species. • This problem is discussed in some detail
in Reference (29). There seems to be little assurance from the information in
the literature that a solution to the diesel odor problem is close as its origin
is not even well understood.
Reducing the particulate (smoke) emissions from the diesel engine
is fortunately more straight forward than that of reducing odor emissions. In
the case of particulate emissions, the concentration of the pollutant is easily
3
measured and expressed in quantitative terms (mgm/ft ) and its origin in the
combustion process is reasonably well understood. Smoke (carbon particles)
results when more fuel than can be burnt is injected into the cylinders and,
hence, becomes a problem only at lugging and high engine loads. Current
federal smoke emission standards for heavy duty engines are expressed in terms
of exhaust gas stream opacity for various engine operating modes. For extensive
urban use of diesels, it would seem that a reasonable minimum smoke standard
would be that the exhaust not be visible at any engine operating mode. Studies
(30)
have been made which indicate that this requires the particulate concentration
3
be always less than 7 mgm/ft , which corresponds to a smoke meter reading
of about 10% opacity. This is considerably more restrictive than the present
standard of 15-20%, but available diesel emission data indicate it can probably
(3 1, 32)
be met without great difficulty. It should be noted ' that the use of EGR
and injection retarding to reduce NO emissions aggravates the smoke problem.
It is also of interest to compare the particulate emission (gm/mi) of gasoline
and diesel engines for the LA-4 driving cycle. Typical gasoline engine parti-
culate emissions are:
.05 gm/mi - non-leaded fuel
.20 gm/mi - leaded fuel
2-100
-------
Using the conversion factor (C. F. ) of about . 5 to relate driving cycle and engine
dynamometer emissions, the gasoline engine particulate emissions become
. 1 gm/bhp-hr - non-leaded fuel
.4 gm/bhp-hr - leaded fuel
for the engine dynamometer tests. This compares with values of . 2-. 6
gm/bhp-hr given in Reference (27) for diesel engines. Hence on a total
particulate emissions basis, diesel engines are comparable to gasoline engines
using leaded fuels.
2.6.3.2 Three-Valve Carbureted Pre-Chamber (CVCC)
Engines
A recent modification by Honda to the spark ignition gasoline
engine termed the CVCC (Compound Vortex Controlled Combustion) or three-
valve carbureted pre-chamber (stratified charge) engine has proven to have
much lower baseline emissions than the conventional gasoline engine. Emissions
tests ' have been made on Honda modified vehicles using both 4-cylinder
and 8-cylinder engines. As indicated in Table 2. 23, all the vehicles tested
satisfied the 1975 standards for HC and CO without exhaust treatment devices.
The NOX emissions from the CVCC-powered vehicles without EGR were quite
low being between . 7 and 1. 5 gm/mi depending on engine CID. In addition, the
fuel economy data indicate that there is little, if any, fuel penalty associated
with the CVCC modification of the gasoline engine.
The CVCC engines tested were modified versions of standard (pro-
duction type), passenger car engines with only the head, timing gear train,
and fuel system modified to accept the pre-chamber arrangement for the ini-
tiation of combustion. Work thus far on the CVCC engine concept has shown
no reason why it cannot be user! on intermediate to large V-8 engines suitable
for medium duty trucks. Initially it was thought that the CVCC concept was
2-101
-------
(35)
only applicable to small engines but more recent work on a 350 CID, V-8
engine indicates this is probably not the case. 50, 000 mile durability tests
have been made on 4-cylinder, CVCC engines, but as yet the 8-cylinder version
has not been durability.tested. It can be expected that design and development
testing work to adapt the CVCC concept to large V-8 engines will be pushed
rapidly in the next couple of years. If the outcome of those efforts continues
to look promising, then it seems likely that the CVCC engine will become a
major alternative power plant for medium duty vehicles.
2-102
-------
I
t—'
o
TABLE 2. 23
EMISSIONS DATA FOR VEHICLES USING CVCC ENGINES
Engine
1975 CVS-CH Emissions
Average level (gm/mi)
Source
Ref (34)
Ref (34)
Ref (34)
Ref (35)
Cylinders
4
4
4
8
CID
125
125
125
350
Vehicle
Weight(lbs)
(2)
2000 v '
(3)
2000 v '
(2)
3000 v '
4500 ^
HC
. 18
. 24
. 28
. 22
CO
2. 12
1. 75
3. 08
2.95
NO
X
.89
.65
1.56
1. 22
MPG
22. 1
21. 3
19.4
11. 0
(1) No EGR or exhaust gas treatment
(2) Low mileage
(3) 50,000 mile durability test
-------
2. 7 Emission Control Strategies
The preceding sections of this report have identified eight
different emission control systems which are likely candidates for use in
medium duty vehicles to reduce exhaust emissions. Estimates have been
made of their effectiveness in emission reduction, effects on fuel economy
and vehicle performance. In addition, the capabilities of two alternative
engines to the conventional gasoline engine have been similarly evaluated.
From this selection of possible control systems, a wide range of control
strategies can be hypothesized by taking into account the lead times
required to bring these systems into the production stage.
The problem can be reduced to tractable proportions by
focussing on a few strategies which may be taken as representative of
the range of choices that is possible. Considering only conventional
gasoline engines, the eight applicable control systems reduce to three
basic approaches: (1) the use of improved fuel control (carburetion or
fuel injection), (2) the use of catalytic converters and (3) the use of
thermal reactors. Another factor is the alternative engine which can be
shown entering production at appropriate times and in differing quantities
to achieve a mix of vehicles equipped with different types of engines.
To evaluate the impact of different control strategies, a
computer program has been devised to evaluate the projected annual
emissions from medium duty vehicles through 1990 assuming implementation
of a number of selected control strategies. A description of the computer
program is included in a subsequent section. Specific examples of
several representative control strategies that were subjected to analysis
on the computer are described below. Project constraints on time and
2-104
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funds limited the number of possibilities that could be investigated to a
total of six.
2.7.1 Conventional Gasoline Engines
A listing of the add-on emission control systems and their
associated reduction factors is given in Table 2.10. To provide a simple,
inclusive method for ranking each system according to its control
effectiveness, a mean overall reduction factor for each system has been
computed. This mean factor, obtained by averaging the individual
pollutant factors, is substantially the same regardless whether the HC +
CO + NO or the HC + NO factors are averaged. The usefulness of
xx
these mean factors lies in correlating the control systems with lead time
information to program a decreasing emissions schedule. A summary of the
mean reduction factors, the year of system availability and the relative
ranking in effectiveness of each control system is given below.
CONTROL SYSTEM REDUCTION FACTORS
Mean Reduction Factor
No.
0
1.
Control
System
EM°
EM° + El + FC
Control Year
HC+CO+NO
X
1.0
0.98
HC+NO
X
1.0
0.98
Rank
0
8
Available
1972
1975
- + AI + EGR
2. EM° + El + 1C + QHI 0. 60
+ AI + EGR
3. EM + El + 1C + QHI
+ EGR + AI + OC
0.31
0.62
0.39
1975
1977
2-105
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Mean Reduction Factor
No.
Control
System
HC+CO+NO
HC+NO
x
Control Year
Rank Available
4. EM + El + 1C + QHI 0. 14
+ EGR + RC + AI/CAI
+ OC
5. EM° + El + EFIC 0. 14
+ EGR + RC/OC
6. EM° + El + 1C + QHI 0.41
+ EGR + LTR
7. EM°+ El + FC 0.20
+ EGR + AI + RTR
8. EM° + El + FIG + IQHI 0.35
+ AI + EGR
0. 14
0. 14
0.44
0. 13
0.38
1978
1979
1977
1977
1978
Fuel control systems are identified by numbers 2 and 8,
catalytic systems by numbers 3, 4 and 5, and thermal reactors by numbers
6 and 7. In combining these systems into a time-sequenced control scheme,
the practical, economic realities must be recognized. For example, it
would not be conceivable to consider specifying the use of a thermal reactor
for one model year of vehicles and then to schedule a changeover to a
catalytic converter system for the following model year.
2.7.1.1 Catalytic Converter Approach
Tabular data in the preceding section show that catalytic
converters are potentially the most effective devices in achieving the
2-106
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lowest possible emissions among the set of devices that have been analyzed.
Consequently, the most stringent emissions reductions will be realized using
the catalytic approach. The following schedule represents a realistic
*
maximum emissions reduction strategy.
Control System No. Model Years in Effect
2 1975, 1976
3 1977, 1978
5 1979, onward
This implementation strategy is representative not only of the
most stringent control schedule but also probably the most desirable in a
practical sense. It represents an evolutionary implementation of a catalytic
system that results in an ultimate system that not only is highly effective
in reducing emissions but accomplishes this at a very small cost in fuel
economy. Thus other control strategies using catalytic devices were not
considered useful.
2.7.1.2 Fuel Systems/Reactor Approach
As indicated by the heading of this section, the use of improved
fuel control systems and thermal reactors in an emission reduction
implementation scheme is possible in combination or singly. Of the two
reactor systems listed, the rich thermal reactor can be disregarded as a
viable approach. While a high level of emission reduction has been
predicted for the rich reactor, the fuel penalty inherent with this system
is just too costly and unacceptable in view of recognized need to conserve
the supply of fossil fuels.
* Note that the "catalytic converter approach" utilizes a non-catalytic
system (#2) as the first stage of the implementation scheme.
2-107
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Two fuel control strategies were selected for computer
evaluation:
STRATEGY I
Control System No. Model Years in Effect
2 1975 onward
STRATEGY II
2 1975 - 1977
8 1978 onward
Strategy I represents a minimum approach to control with an
average emission reduction of approximately 40% in each of the three
major pollutants from the 1972 baseline levels. Strategy II follows that
of I through 1978 when advanced carburetion and quick-heat induction
systems are introduced with additional reductions achieved in HC, CO
and NO together with improved fuel economy.
5C
Only one reasonable strategy appears to exist for a combined
fuel control/reactor approach.
Control System No. Model Years in Effect
2 1975, 1976
6 1977 onward
While system 6 does not represent an improvement in either emissions
reduction or fuel economy relative to system 8, it is an available alternative
that needs to be assessed on the basis of cost effectiveness.
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Z.I.2 Alternative Engines
The discussion of alternative engines in Section 2. 6. 3 has made
clear that at this time the lightweight dies el engine is the only new engine
that can be realistically projected for use in medium duty vehicles. For
this application, the use of a turbocharged, pre-chamber type of a high-
rpm diesel equipped with EGR is envisioned. Sufficient information exists
on this type of engine, both in terms of its exhaust emissions performance
and fuel economy as well as costs, to permit a meaningful evaluation of its
potential role as a low emissions power plant for the medium duty vehicle.
The three-valve, stratified-charge engine concept appears to
offer the possibility of converting the conventional gasoline engine into
a low-polluting power plant without the use of add-on control systems.
Emissions performance data on engines of a size (CID) required for
medium duty vehicle applications exist on only one, makeshift engine. Data
on engine durability, costs and other important factors just are not
available upon which an analysis can be made currently.
Diesel engines are projected as being in limited quantity
production by 1978 and full-scale production by 1980. Two computer runs
were made using a mix of diesels and conventional gasoline engines equipped
with (1) the most stringent control system based on the catalytic converter
approach and £)the fuel control system approach.
2.7.3 Computer Simulation of Medium Duty Emission
Control Strategies
As discussed in the previous sections, there are various control
strategies that could be used to reduce emissions from medium duty vehicle.
2.- 1 09
-------
In order to quantitatively assess the costs and benefits of the various
strategies over a period of years, it is necessary to calculate the total
yearly HC, CO, NO emissions (tons/yr) from all the medium duty
J\.
vehicles on the road as well as the dollar costs (initial, operating,
maintenance) associated with the emissions reduction in a given year.
In any particular year, the MDV on the road represent a mix of vehicle
ages, weight and body shapes, engine types, and emission control systems.
The calculation of the total emissions and costs each year using a specified
control strategy is straight forward, but cumbersome, because of the
large amount of input data required to describe the medium duty vehicles
$
in operation. Hence a computer program (AMTEC) was written to
calculate the emissions and costs pertinent to various control strategies.
A detailed description of the program along with a Fortran listing is given
in Appendix A-8. In this section, only the general approach taken in making
the calculations, the required input information, and the primary program
output quantities are discussed. Results obtained using AMTEC are
presented in the next section.
In developing the program, the medium duty vehicles were
divided into categories or groups according to vehicle weight and use (ex.
6,000 - 10,000 Ib. trucks, 10,000 - 14,0001b. motor homes). The
vehicles in each group were then characterized by model year, engine type,
and emissions control system. For example, one might have a 1977
6, 000 - 10, 000 Ib. truck with a dies el engine equipped with EGR. Next it
was necessary to characterize each vehicle/engine/control system
combination in terms of emissions, fuel consumption, and initial and
operating costs. In the case of emissions, the uncontrolled emissions
* Analysis of Medium (duty) Truck Emissions (and) Costs
2-1.10
-------
for each model year vehicle/engine combination were input along with the
reduction factors for a series of emission control systems which might be
used with the engines. The baseline fuel consumption of each vehicle/
engine combination was also input along with the fuel penalty associated
with each of the emission control systems. It was assumed that the
baseline fuel economy depended only on the vehicle/engine combination and
not the model year. The costs (initial, operating, and maintenance) were
input according to engine type and control system. The costs were taken
to be independent of model year and vehicle group depending only on engine
type and control system. In addition to characterizing the vehicle/engine/
control system combinations, it was necessary to characterize the vehicle
operation such as the maintenance program, miles traveled per year, and
scrapage rate. Vehicle operation was characterized for each vehicle
group.
The number of vehicles of each category that are on the road
in any given year depends on the sales in previous years and the scrappage
rate. The sales for each year are described in terms of vehicle group,
fraction of vehicles in each group having each engine type, and the control
system used on each engine type. Vehicle sales data was used going back
to 1950 and projected to 1990. A summary of the input information
required for AMTEC is given in Table 2.24. Most of the information needed
was generated during the present medium duty truck emissions study and
thus is documented in this report. When information from other sources
is used, the source is noted in Table 2.24.
The time period considered in the present study -was 1970 - 1990.
The primary AMTEC output quantities, which are listed below, are
calculated for each year of that period.
2 , U1
-------
TABLE 2.24
SUMMARY OF REQUIRED INPUT INFORMATION
FOR THE AMTEC PROGRAM
Input Information
1. Sales for each year for each
vehicle group (1950 - 1990)
Source
19.50-1972, Reference (38)
1973-1990, P.R/1* (Figures 3.5-10)
2e Fraction of engine types for each 1950-1972, Reference (38)
year and vehicle group 1973-1990, C.S.
3. Baseline fuel economy (MPG)
for each vehicle group and
engine type
P. R. (Figure 2. 11)
4. Miles traveled per year for each Reference (37)
vehicle group and vehicle age
5. Baseline H. C. , CO, NO
x
emissions for each vehicle
group and model year for each
engine type
1950-1972, Reference
1973-1990, P. R. (Figure 2.7-9)
6. Fraction of vehicles of a given Reference (36)
age remaining on the road for
each vehicle group.
(1) P. R. - Present report
(2) C.S. - Specified emission control strategies
(3) The same trend with model year of pre-controlled emissions was
assumed for MDV as was found in Reference (39) for LDV.
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10.
Table 2.24 (cont'd. )
Input Information
7. Emission reduction factors
for HC, CO, NO for each
combination of engine type
and control system
8. Fraction of engines of each
type equipped with a given
control system in each model
year
9. Fuel penalty factors for each
engine and control system
combination
Fuel factors relating baseline
fuel economy of various
alternative engines to the
conventional gasoline engine
11. Incremental cost (initial and
maintenance) for each engine
and control system combination
Source
P.R. (Tables 2. 14, 2.22)
C.S.
P.R. (Tables 2. 15, 2.22)
P.R. (Table 2. 22)
P. R. (Tables 3. 6-9)
2-113
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(1) Total HC, CO, NO emissions (tons/year)
x
(2) Total gasoline and diesel fuel consumed (gal/year)
(3) Incremental fuel consumed due to the use of emission
control systems and alternative engines (gal/year)
(4) Incremental costs due to the use of emission control
systems and alternative engines (dollars/year)
As indicated in Appendix A-8, the contribution to the total
emissions, fuel consumption, and costs of the vehicles in each vehicle
group is determined for each year by summing the contributions of the
vehicles in that group from all model years. Then the contributions of the
different vehicle groups are added to obtain the total emissions, fuel
consumption, and costs for the year of interest. AMTEC results for
various control strategies are presented in the next section.
2.7.4 Results of Computer Study
This section will discuss only those results of the computer
program study which involve emissions and fuel economy. A total of seven
different runs (designated as Cases I through VII) was processed and the
results obtained for these specific situations are summarized herein.
Table 2.25 contains a listing of the seven test cases together
with the general emission control approach used, the control systems
involved and the year of their introduction into production vehicles. Two
types of runs were made; one type in which all vehicles used only conventional
engines (Cases I-V) and the other, in which a specific mix of conventional
and diesel engines was considered. Attention is called to the fact that the
'2-114
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TABLE 2.25
SUMMARY OF COMPUTER RUNS
A. Conventional Gasoline Engines Only
Case No. Control Approach
I None (1972 reference)
II Fuel Control
III Fuel Control
IV Thermal Reactor
V Catalytic Converter
B. Conventional Gasoline Engines and
VI Fuel Control
VII Catalytic Converter
Contro1 ***
System No.
None
2
2
8
2
6
2
3
5
**
Diesels (w/EGR)
2
8
2
3
5
Year
1972
1975
1975
1978
1975
1977
1975
1977
1979
1975
1978
1975
1977
1979
* In all cases the conventional engine was a 350 CID V-8
** The Diesel was taken to be equivalent to the 350 CID V-8
(same CID, turbocharged, pre-chamber, w/EGR)
*** See Table 2.10 for description - these systems are used
only on conventional engines
2-115
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conventional engine, in all cases, was assumed to be a 350 CID V-8. Also
the diesel, in all cases, was assumed to be a lightweight, turbocharged,
3
pre-chamber engine with a 350 in displacement and equipped with EGR. An
assumed schedule of the chronological sequence and the quantity of diesel
engine introduction into the MDV population is outlined in the following table.
ASSUMED SCHEDULE OF INTRODUCTION OF DIESEL
ENGINES FOR COMPUTER STUDY-
PERCENTAGE OF TOTAL VEHICLE ANNUAL SALES
Trucks-GVW, Ibs. Motor Homes-GVW, Ibs.
Year 6,000-10,000 10,000-14,000 6,000-10,000 10,000-14,000
1978
1979
1980
1981
1982
5
10
25
25
25
10
20
35
50
65
5
10
25
50
50
10
20
35
65
65
1990 25 65 50 65
The computer program has a built in capability to divide the MDV category
of vehicles into four groups according to GVW range and truck/motor home
type. The results presented in this report pertain to the composite results
only and include the entire range of GVW from 6,000 to 14, 000 Ibs. for
all MDV vehicles.
Annual emissions data for an MDV population using only con-
ventional engines and subjected to the four emission control implementation
strategies shown in Table 2.25 are graphically illustrated in Figure 2. 19
-------
through 2.21. A separate presentation is made for HC, CO and NO and on
each plot a reference emission curve is shown corresponding to a situation
where the emissions of all new vehicles are maintained at 1972 baseline
levels. The upward curvature of the reference trace merely reflects the
increasing number of vehicles on the road in accord with the projected
sales. Emission curves corresponding to the different control strategies
will tend to curve upward (sooner or later depending upon degree of
emission reduction) for the same reason.
The graphical data show that the relative effectiveness (in order
of rank) of the four emission control strategies remains the same for all
three pollutants. Case II, fuel control (system No. 2), is least effective
while Case V, catalytic conversion (systems No. 2, 3 and 5) is the most
effective. The two intermediate levels of effectiveness are substantially
equivalent and correspond to the lean thermal reactor approach (Case IV)
and the improved fuel control approach (Case III).
Similar data are graphically shown in Figures 2.22 through
2.24 for the situation where a mix of conventional and diesel engines is
used in the MDV category of vehicles. Note that only the two implementation
control strategies found to be most effective in the previous computer runs
are used here. These two are the catalytic converter approach (here
designated as Case VII) and the improved fuel control approach (designated
Case VI). These control strategies are applied only to the conventional
engines. Diesel engines are assumed to be equipped only with an EGR
system.
It is instructive to compare the HC, CO and NO emission plots
for the two conditions corresponding to conventional engines only and
2-117
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C/J
o
o
oo
O
X
1972 74 76 78 80 82 84 86 88 90
0.2
0.1
Figure 2.19 ANNUAL HC EMISSIONS AS FUNCTIONS OF CONTROL STRATEGY
CONVENTIONAL GASOLINE ENGINES ONLY -- MDV
2-118
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CO
CO
O
O
O
CASE CONTROL
SYSTEM NO.
1972 74 76 78 80 82 84 86 88 90
YEAR
Figure 2.20 ANNUAL CO EMISSIONS AS FUNCTIONS OF CONTROL STRATEGY
CONVENTIONAL GASOLINE ENGINES ONLY -- MDV
2-119
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CASE CONTROL
Mft ...SYSTEM NO.
NO.
oo
O
LL.
O
V)
Z
O
•\yj2 74 76 78 80 &2 84 86 88 90
0.2
0.1
Figure 2.21 ANNUAL NOX EMISSIONS AS FUNCTIONS OF CONTROL STRATEGY
CONVENTIONAL GASOLINE ENGINES ONLY - MDV
2-120
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0.9 r
O
CO
2
O
O
I
1972 74 76 78 80 82 84 86 88 90
0.1
Figure 2.22 ANNUAL HC EMISSIONS AS FUNCTIONS OF CONTROL STRATEGY
CONVENTIONAL ENGINES AND DIESELS (W/EGR) -- MDV
2-121
-------
^AOC CONTROL
CASE SYSTEM NO.
6O
O
O
CO
O
O
76 78 80 82 84 86 88 90
Figure 2.23 ANNUAL CO EMISSIONS AS FUNCTIONS OF CONTROL STRATEGY
CONVENTIONAL ENGINES AND DIESELS (W/EGR) -- MDV
2-122
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CONTROL
CASE... SYSTEM NO.
NO.
1972 74 76 78 80 82 84 86 88 90
Figure 2.24 ANNUAL NOX EMISSIONS AS FUNCTIONS OF CONTROL STRATEGY
CONVENTIONAL ENGINES AND DIESELS (W/EGR) -- MDV
2-123
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conventional/diesel engines. Because of the very low inherent HC and CO
emissions of the diesel engine, it is seen that the combined use of
controlled conventional engines and' diesels results in lower emissions of
these two pollutants than if only controlled conventional engines are used.
On the other hand, a homogeneous population of conventional engines
equipped -with catalytic converters produces lower NO emissions than a
heterogeneous population of similarly controlled conventional engines and
EGR equipped diesels. The reason for this result is that the NO emissions
5C
from a diesel engine with EGR are higher than those of an equivalent
conventional engine fitted with a catalytic converter system (reducing).
A note of interest is the observation that the improved fuel
control strategy (comprising control systems No. 2 and 8) is rendered
more effective in achieving lower total annual emissions for each of the
three pollutants (especially HC and CO) if the heterogeneous engine mix
is used. In fact the difference in effectiveness compared with the
catalytic converter approach becomes rather small. This fact could be
highly significant if the catalytic approach should become unworkable due
to developmental obstacles or possible durability problems related to the
heavier engine loading of the MDV group.
Figure 2.25 presents a graphical summary of the fuel penalties
associated with each of the four control strategies used with the medium
duty vehicle group in the situation when only conventional gasoline engines
are considered.. The ordinate shows the percentage of the total annual
fuel consumed which is attributable to the use of the emission control systems.
NOTE: To avoid confusion in dates, it should be observed that the
introduction of control systems occurs at the beginning of
a. designated year while annual emissions are computed
over the entire period of the designated year.
2-124
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o
o
cc
I-
o
o
o
m
D
CO
<
cc
<
LLJ
a.
O
o
o
_l
111
o
72 74
CASE
76 78
80 82
YEAR
84
86 88
90
CONTROL
SYSTEM NO.
2,6
2,3,5
2,8
Figure 2.25 ANNUAL FUEL PENALTY AS A FUNCTION OF CONTROL STRATEGY
CONVENTIONAL GASOLINE ENGINES ONLY -- MDV
2-125
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Those systems which produce the greatest reductions in emissions are
also seen to be the ones incurring the smallest fuel penalties. The sharp
break observed in the trace, associated with the catalytic control system is
explainable by the transition from a system (No. 3) with poor economy to
one (No. 5) with a very low. fuel penalty. It should be noted that the
catalytic system requires the use of lead-free gasoline.
Fuel data corresponding to the heterogeneous engine mix
situation is shown in Figure 2. 26. In this case we see that a saving in
fuel consumption actually occurs when diesels, with their excellent fuel
economy, are partially substituted for conventional engines equipped
with control systems. The ordinate shows the percentage of fuel conserved.
This value was calculated as follows. First the total annual quantity of
fuel consumed by the medium duty vehicle group was identified (from the
computer printout) for the case of conventional engines only when
equipped with each of the control systems identified in Figure 2.26.
Similar fuel data was identified for the case of the conventional engine/
diesel engine mix with the same control systems. Subtracting the
corresponding set of figures for each year and dividing this difference by
the larger base figure gave the percentage value for the fuel conserved.
Because the two control strategies considered have substantially equivalent
fuel penalties when used with conventional engines, the fuel savings
attributable to the use of diesels was found to be almost identical for the
two cases. Hence only a single curve is shown in Figure 2. 26. While
these percentage values may appear small, the quantity of fuel involved is
large. For purposes of reference, the annual fuel consumption for the
medium duty vehicle group equipped with conventional engines and operating
at 1972 baseline fuel economy is shown in Figure 2.27.
2-126
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10
v>
uj 7
O
- 6
CQ
in 5
oc
111
V)
O
O
01
£ 3
5?
CONTROL
CASE SYSTEM NO.
NO.
1972 74 76 78 80 82 84 86 88 90
YEAR
Figure 2.26 ANNUAL FUEL ADVANTAGE USING CONVENTIONAL ENGINE/DIESEL
MIX RATHER THAN CONVENTIONAL ENGINES ONLY -- MDV
2-127
-------
1972 74 76 78 80 82 84 86 88 90
Figure 2.27 REFERENCE ANNUAL FUEL CONSUMPTION FOR MDV -- CONVENTIONAL
GASOLINE ENGINES -- NO ADD-ON CONTROL SYSTEMS
2-128
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The emissions projections show that a sizeable impact on the
total annual emissions attributable to the 6,000-14,000 Ib. GVW group of
vehicles can be achieved in a rather short span of time. Using some of
the more effective control strategies, a reduction in emissions of about
40% is predicted by 1980 over the reference situation where all the future
production vehicles are presumed to maintain 1972 emission levels.
2.7.5 Control Strategy Evaluation
In a situation where a number of alternative approaches in
attacking a problem exist, the normal tendency is to attempt an optimized
solution. This is a desirable objective and may be feasible if the specific
criteria for optimization are identified. Reduction of the emissions emitted
by a class or category of vehicles involves many factors which are
interdependent and interact. For example, such factors as level of
emissions control, fuel penalty, costs and vehicle performance are
inter-related. While each factor may be assigned a "weighting" index to
facilitate analysis, such a choice of weighting indexes is completely
arbitrary unless circumstances provide a realistic basis for such an
assessment. It is therefore more meaningful to discuss a possible "best"
approach to emission control of the medium duty vehicle rather than an
optimum approach.
The present discussion of a "best" control strategy is presented
in the context of the data and information developed in this study. ' This
study has perforce relied on estimated or extrapolated data in situations
where experimental information either did not exist or was not available.
Also, the computer study was of a lesser scope than would have been
desirable. Since costs of implementation were not a part of this study
2-129
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(cost analysis is included in Part B, Section 3. 0), this important factor
is excluded here.
The results of the computer study provide a rather clear and
unambiguous evaluation of the several control strategies which were
considered appropriate to the medium duty vehicle. Solely from the
standpoint of emission reduction, the control strategy based on the use
of catalytic converters with conventional engines is demonstrably superior
for HC, CO and NO . The fuel penalty is only slightly higher than the most
?C
economical (but less effectual) system evaluated.
Further reduction of HC and CO emissions is achieved if a
portion of the medium duty vehicle engines equipped with catalysts is
replaced with dies els which incorporate an EGR system. In addition, a
"bonus" is realized by a substantial savings in the quantity of fuel that
is consumed. On the other hand, the introduction of the diesel does incur
a lesser control of NO .
x
The use of the diesel engine as a part of the control strategy
places the improved fuel control approach as an excellent alternative to
the catalytic converter route. While the emission reduction is somewhat
poorer, a fuel "bonus" is realized and the durability will undoubtedly be
superior to the catalytic converters.
The "best" control strategy, defined as achieving a high
reduction of emissions combined with a low fuel penalty, is that utilizing
a blend of conventional engines equipped with catalysts and diesel engines
equipped with EGR. A likely alternative choice is that wherein the improved
fuel system approach is substituted for catalysts.
2-130
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Diesels are usually associated with exhaust smoke and odor.
While the pre-chamber diesel achieves better control over these exhaust
characteristics, the possibility exists that concentrations of large numbers
of diesels in urban areas may create objectionable problems with regard
to smoke and odor.
2-131
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3.0 ECONOMIC ANALYSIS PART B
3.1 Introduction and Summary
The purpose of the study is to develop and analyze the relation-
ships between different control levels and the cost-of-owncrship of representative
6-14,000 Ibs. GVW vehicle-engine types equipped with various engine-emission
control systems. The time span of interest is 1972-1080. The term cost-of-
ownership is defined as the cost to the final vehicle user. The economic
analysis is part of the preceding study program which entailed a technical
evaluation of emission control approaches and an assessment of emission limits
for 6-14,000 Ibs. GVW vehicles.
Projected sales of the various types of vehicles which comprise
the 6-14,000 Ibs. GVW vehicle population are developed in section 3.3. The
vehicles within this GVW range are divided into two iveight categories;
6-10,000 Ibs. and 10-14,000 Ibs. The vehicles in the first category predominate.
In recent years they have represented 20-24 percent of all U.S. sales of
trucks and buses. Sales of the 10-14,000 Ibs. vehicles have generally accounted
for less than 2 percent of total U.S. sales.
The derivation of the costs of the proposed emission control
devices is described in section 3.4. Diesel engine costs are also included
in this section. The cost estimates are incremental costs relative to the
1972 spark ignition engines. Because of the uncertainties associated with a
number of the devices, cost bounds are developed representing low, anticipated
and high cost estimates.
Emission control system costs are synthesized in section 3.5.
Eight systems for use with spark ignition engines and two diesel engine
systems are considered. Separate costs are first shox\m for each of the
three major cost categories: initial or sticker prices, incremental
maintenance and operating costs. These costs are then combined into total
costs representative of 50,000 miles or 5 years of vehicle operation.
3-1
-------
The resultant costs vary widely. The systems which employ
catalytic converters to control pollutants have the highest costs. Diesel
engines, despite their relatively high initial cost, offer long term savings
relative to the baseline engine because of their lower fuel consumption.
t
The emission control alternatives considered are presently in
varying stages of development. Estimated lead times for the systems are
discussed in section 3.6. They vary from about 2 to 5 years for systems
designed for use with spark ignition engines. The development of a domestic
family of diesel engines is estimated to require 8-10 years. The production of one
diesel engine with relatively wide applicability to medium duty vehicles could
be achieved sooner, by 1978 or 1979.
The costs and effectiveness of the systems are examined in
section 3.7. Three approaches or control strategies are delineated for
conventional gasoline engines. These are defined according to their major
emission control device. They are improved carburetion, thermal reactor, and
catalytic converter. The strategies are not mutually exclusive. For example,
improved carburetion features are also used with thermal reactors and
catalytic converters.
The greatest reduction of pollutant emissions is achieved with
catalytic converters. The cost incurred, however, is high. A mix of diesel
powered vehicles, equipped with ECR and spark ignition powered vehicles with
improved carburetion provides almost the same level of emission control at
significantly lower costs. The latter combination appears as the "best"
approach based on the analysis performed.
3-2
-------
A gross estimate of the potential impact of certification costs
is made in section 3.7.1. The final section discusses the potential impact
of the costs of emission control systems on the lease costs of such vehicles.
3.2 Conclusions
The conclusions of the study are:
1. The use of improved carburetion for emission control of
spark ignition engines together with the introduction of
diesel engines appears as the best control strategy for
medium duty vehicles. This approach would reduce annual
emissions of HC, CO and NO., by 77, 81 and 64 percent (com-
pared to 1972 baseline), respectively by 1989. The 15 year
cost of this approach is $2 billion.
2. A small, further improvement in NO emission reductions can
A
be obtained by a mix of diesel and standard gasoline engines
where the latter are equipped with catalytic converter
systems. The 15 year cost of this approach is considerably
higher, $3.4 billion.
3. Diesel engines equipped with EGR result in significant
emission reductions and at the same time provide good fuel
economy. Fuel savings more than off-set the higher initial
price of such engines.
4. The improved carburetion and catalytic converter approaches
are the systems of choice in the absence of diesel engines.
Implementation of the former systems will result in the
reduction of all pollutants by about 60 percent by 1989 at a
total cost of $3.7 billion. The latter systems will reduce
emission levels of HC by 79, CO by 72 and NO by 83 percent
A
by 1989. The cost incurred, however, is $5.3 billion.
3-3
-------
5. Lean thermal reactor and improved carburetion strategies
result in about equal effectiveness. The former costs
more, primarily because of the higher fuel penalty
associated with it.
6. Precise estimates of certification costs cannot be made
until the requirements, engine families and vehicle types
are firmly defined. A preliminary analysis indicates,
however, that the potential impact of certification costs
could be significant, particularly for the smaller manu-
facturers .
7. The cost per mile of operation of pollution control systems
is generally less than $.01 per mile. The potential impact
of this cost on lease charges is, therefore, not considered
significant.
3-4
-------
3.3 Sales Projections for 6-14,000 GVW Vehicles
3.3.1 Introduction
The vehicles within this GVW range fall into two clearly demarked
weight cateogries; 6-10,000 Ibs. and 10-14,000 Ibs. The vehicles in the
6-10,000 Ibs. GVW category predominate. In recent years they have accounted
for 20-24 percent of all U.S. sales of trucks and buses. Sales of vehicles
in the 10-14,000 Ibs. GVW category have always represented less than 2 percent
of total sales, and in many years less than one half of one percent.
In recognition of this sharp distinction, sales projections are
made separately for the two weight categories of vehicles. All data employed,
unless noted otherwise, are obtained from information published by the Motor
Vehicle Manufacturers Association of the U.S., Inc.
3.3.2 Sales Projections for 6-10,000 Ibs. GVW Vehicles
Total U.S. sales of trucks and buses are shown in Figure 3.1.
A least square curve is fitted to the data and extended to 1980. The broken
lines represent + 1 ^*" values. Computation was done as follows:
(T ^
Annual sales are estimated to increase from 2.5 million in 1973 to 3.1 million
in 1980.
Comparable data for 6-10,000 Ibs. GVW vehicles are shown in
Figure 3.2. Visual inspection shows that a straight line may not provide the
best indicator of future sales. The most recent data (1972) indicates a
sharp rise in the sales of these vehicles. Thus, the straight line projection
would tend to underestimate future sales if this trend continues. An
alternative projection was, therefore, made which takes this recent trend into
account.
3-5
-------
3400
3200
3000
2800
s
o
- 2600
co
LLJ
V)
03
08
CO
*
u
CO
Ul
CO
CO
=5
2400
2000
1800
1600
0 1400
1200
1000
800
10-
58 60 62 64 66 68 70 72 74 76 78 80
YEARS
Figure 3.1 U.S. SALES OF TRUCKS AND BUSES
3-6
-------
800
700
600
5"
o
CO
GO
O
o
to
CO
li
o
D
cc
CO
LU
CO
CO
500
400
300
200
100
58 60 62 64 66 68 70 72 74 76 78 80
YEARS
Figure 3.2 U.S. SALES OF 6-10,000 LBS GVW TRUCKS
3-7
-------
Initially, the percent of 6-10,000 Ibs. GVW truck sales of total
truck sales were computed and projected through 1980 (Figure 3.3). Next, the
percentages from this regression line were multiplied by corresponding values
from the regression line in Figure 3.1 for each year. The resultant values
are plotted in Figure 3.4. They form the parabolic curve. The straight line
in Figure 3.4 is the regression line from Figure 3.2. The two projections
compare very closely until 1972 where they begin to diverge.
The two lines bound our estimate of sales of 6-10,000 Ibs. GVW
vehicles for the 1973-1980 time frame. The combined U.S. manufacturers'
estimate of 1973 sales for this category of vehicles is about 565,000 units.
The parabolic projection yields an estimate of 540,000 units, the straight
line projection about 527,000 units.
3.3.2.1 Sales Projections by Body Types
Four body styles are included in the study: Pickups, Van/Panel
trucks, Multistop vans, and Cab/Cowl/Base Chassis and Platform trucks.
Together they account for more than 90 percent of the vehicles in the 6-10,000
Ibs. GVW weight category. The remainder consists of passenger and special
purpose vehicles which are outside the scope of the study.
Existing data do not permit a separate breakout of recreational
vehicles. In fact, all body styles are used for this purpose. Recreational
vehicles are discussed separately in Section 3.3.4.
The percent of sales of 6-10,000 Ibs. GVW trucks by body types is
shown in Table 3.1 for the years 1966-1971.
3-8
-------
80
Figure 3.3 % 6-10,000 LBS GVW TRUCK SALES OF TOTAL U.S. SALES
OF TRUCKS AND BUSES
-------
800
700
§
B 600
Vi
CO
§
o
500
CO
V)
*
u
D
cc
I-
O 400
CO
CO
CO .
300
CO
LLJ
200
100
58 60 62 64 66 68 70 72 74 76 78 80
YEARS
Figure 3.4 ESTIMATED U.S. SALES OF 6-10,000 LBS GVW TRUCKS
3-10
-------
Table S01 Percent of U.S. Sales of Trucks by Body Types
Year Pickup Van/Panel Multistop Van Chassis
26.4
21.4
19.0
21.1
21.7
15.3
1966
1967
1968
1969
1970
1971
64.2
64.3
69.9
63.9
56.0
57.5
1.0
3.0
2.0
3.8
12.4
13.5
8.0
9.0
7.0
9.7
8.5
7.1
The fraction of vehicles in this weight category which are pickups
has declined in recent years. The projection for this body style as a percent
of total sales in this weight category is shown in Figure 3.5. The resultant
sales projections are presented in Figure 3.6. They are computed by
multiplying the percentages in Figure 3.5 by the two sales projections shown
in Figure 3.4. Although the number of pickup trucks as a percent of total
sales is expected to decline slightly, the number of units sold is shown to
increase, reaching sales of 400,000-450,000 units by 1980.
The sales of the other body types are estimated on the basis of
the following factors.
Body Type
Van/Panel
Multistop
Chassis
% of Sales of
6-10,000 Ibs. CVW Vehicles
14
8
18
The resultant sales projections, computed as indicated above, are shown in
Figures 3.7, 3.8 and 3.9.
3-11
-------
00
u
oc
I-
Q.
D
U
a.
LL
O
u
IT
80
70
60
50
40
30
20
10
66 68
70
72 74 76 78
80
YEARS
Figure 3.5 % U.S. SALES OF PICKUP TRUCKS OF TOTAL SALES
OF 6-10,000 LBS GVW TRUCKS
3-12
-------
600 i
_ 500
t/t
b
o
o
00
tt.
X.
O
a.
O
2
400
300
200
100
73 74 75 76 77 78 79 80
YEARS
Figure 3.6 PROJECTED SALES OF PICKUP TRUCKS
120
~ 110
§
o
100
V)
X.
O
cc
I-
<
0.
<
>
o
73 74 75 76 77 78 79 80
YEARS
Figure 3.7 PROJECTED SALES OF VAN/PANEL TRUCKS
3-13
-------
§
o
1—
z
CO
o
cc.
\-
a.
CO
O
O
73 74 75 76 77 78 79 80
YEARS
Figure 3.8 PROJECTED SALES OF MULTISTOP VANS
150
73 74 75 76 77 78 79 80
YEARS
Figure 3.9 PROJECTED SALES OF CHASSIS AND PLATFORM TRUCKS
3-14
-------
Shifts in preference for a particular body type, particularly in
its application as a recreational vehicle can alter the relative percentages
and sales projections. The latter three body types, Van/Panel, Multistop and
Chassis appear most sensitive in this respect and the sales projections must
be considered accordingly.
3.3.3 Sales Projections for 10-14,000 GVW Vehicles
Sales of these vehicles for 1958-1972 are shown in Figure 3.10.
Historically, these vehicles have comprised only a very small percentage,
less than 2 percent, of total U.S. sales of trucks and .buses. The past two
years, however, have witnessed a relatively large growth of sales of vehicles
in this category, with 1972 sales amounting to about 45,000 units. This
increase is believed attributable largely to the growing popularity of
recreational vehicles, particularly of motor homes.
The sales projections shown by the broken lines in Figure 3.10, are
based on percentages of total U.S. sales of trucks and buses. The three
projections represent sales of vehicles in this weight categories amounting
to 2, 4 and 6 percent, respectively, of total sales shown in Figure 3.1. Our
best estimate is that the 4 and 6 percent lines bound projected sales for the
1973-1980 period. Manufacturers' estimates place sales of vehicles in this
category at about 100,000 units in 1973. This represents 4 percent of the
estimated total sales of all trucks and buses.
3.3.3.1 Sales Projections by Body Types
Vehicles in the 10-14,000 Ibs. GVW category consist primarily of
two body types -- multistop van and chassis. No pickups or van/panel trucks
of this weight are manufactured. The proportion of the two body types sold
between 1966 and 1970 is shown in Table 3.2.
3-15
-------
200
-5 180
b
§
1—
Z 160
O
^>
T-
6
^
CO
O
cc
00
LU
CO
CO
140
120
100
80
60
40
20
58 60 62 64 66 68 70 72 74 76 78 80
YEARS
Figure 3.10 U.S. SALES OF 10-14,000 LBS GVW TRUCKS
-------
Table 3.2 Percent of Sales of 10-14,000 Ibs. GVW
Vehicles by Body Type
Year Multistop Van Chassis
1966 43.5 55.3
1967 51.2 48.2
1968 42.7 57.0
1969 59.9 39.7
1970 46.7 53.1
No trend is discernible. A 50-50 split between these body types
appears a reasonable estimate. Both body types are used for recreational vehicles.
The relative proportions of each type used for this purpose are not known.
3.3.4 Recreational Vehicles
All the body types noted in the previous sections can be and are
used as recreational vehicles. Recreational vehicles can be divided into two
general categories -- truck campers and motor homes. Truck campers represent
numerically the larger of the two categories. They consist of camper bodies
mounted on pickup or chassis trucks. Such vehicles are frequently multi-
purpose in use. They may be employed for personal transportation or commercial
use and converted to recreational vehicles when desired. Motor homes
generally are used only as recreational vehicles. In the past, they have
been fabricated by motor home manufacturers on chassis purchased from
automobile manufacturers.
Recent sales of recreational vehicles are shown in Table 3.3. The
sales data base used is from "Recreational Vehicles Facts and Trends".
1971 data will not be available until June 1973.
3-17
-------
Table 3.3 Sales of Recreational Vehicles
Year
Truck Camper
Motor Home
Total
1967
1968
1969
1970
1971
61,600
79,500
92,500
95,900
107,200
9,050
13, 00
23,100
30,300
57,200
70,650
92,700
115,600
125,200
164,400
% of 6-14,000 GVW
Vehicle Sales
23.9
23.7
28.0
30.6
33.4
All of the vehicles are in the 6-14,000 Ibs. GVW range. Past and projected
future sales of such vehicles are included in the sales projections contained
in the previous sections.
One third of all vehicles in the 6-14,000 Ibs. GVW range were used,
at least partly, as recreational vehicles in 1971. Sales of such vehicles
more than doubled between 1967 and 1971 demonstrating their increasing
popularity. This trend is expected to continue over the next few years.
Beyond that, their sales will be strongly influenced by the state of the
economy, and more specifically by the development of new recreational areas
and facilities to meet the demands of these types of vehicles.
3.3.5 Engines Used in 6-14,000 Ibs. GVW Vehicles
Engine data for the vehicles is based on manufacturers' sales
projections for 1973. Engines are divided into the following 5 categories
for this analysis:
16 225-250 CID
16 250-300 CID
V8 300-320 CID
V8 330-360 CID
V8 390-500 CID
All major manufacturers produce engines in each of the V8 categories.
Additionally, each manufacturer offers at least one 16 engine option.
3-18
-------
The manufacturers' sales projections do not permit a clear-out
categorization by body type. Consequently, the totals represent more valid
bases for comparison than the numbers shown for the individual body types.
The data are shown in Table 3.4.
The V8-330-360 CID engine predominates in 6-10,000 Ibs. GVW vehicles,
This is due largely to its extensive use in pickup and chassis trucks. Van/
Panel and multistop vans are frequently sold with smaller engines as well.
The distribution of engines in the 10-14,000 Ibs. GVW vehicles is
somewhat different. The largest V8 is the most common engine due to its
extensive use in motor homes. The second engine in order of usage is the
small V8 300-320 CID.
3-19
-------
Table 3.4 Engines in 6-14,000 Ibs. GVW Vehicles Based on
1973 Manufacturers' Sales Projections
,. 16 225-249
16 250-300
V8 300-320
V8 330-360
V8 390-500
to
o
6-10,000 Ibs GVW Vehicles
Pickup and Chassis
Van/Panel Trucks
Multistop Vans
Motor Homes
Subtotals
10-14,000 Ibs. GVW Vehicles
Chassis
Multistop Vans
Motor Homes
Subtotals
GRAND TOTALS
9,680
2,000
1,000
2,680
250
2,000
2,250 .
4,930
23,982
2,591
1,000
37,573
4,478
4,700
9,178
36,751
62,630
23,320
85,950
1,200
2,000
22,870
26,070
112,020
346,247
24,000
3,000
373,247
4,754
12,850
17,604
390,851
62,797
3,850
66,647
200
5,000
28,130
33,330
99,977
-------
3.4 Cost Estimates
3.4.1 Introduction
Incremental sticker prices and maintenance costs of the emission
control devices employed with the spark ignition engine are developed in this
section. Additionally, incremental costs associated with diesel engines are
presented. The cost baseline is the 1972 spark ignition engine incorporating
engine modifications but without add-on devices.
Firm cost information concerning emission control devices presently
in use on light duty vehicles is not readily available. The cost increment
resulting from the addition of these devices is included in the total current
automobile prices.
The devices proposed for use on medium duty vehicles include some
which are similar to those presently employed on light duty vehicles as well
as others which are in various stages of development. Consequently, the cost
estimates presented in this section are preliminary and must be reexamined as
further information becomes available.
The approach taken has been to establish a consistent set of costs;
particularly with respect to the relative cost differences between systems.
Because of the uncertainties associated with the costs of a number of the
devices, cost bounds are developed indicative of low (L), projected anticipated
(A), and high (H) costs.
3.4.2 Emission Control Devices
The emission control devices employed in the eight systems are
listed in Table 3.5. Costs of the devices are described in the sections
following.
3-21
-------
Table 3.5 Emission Control Devices
Device
Electronic ignition
Fast choke
Quick heat intake manifold
Improved carburetion
Advanced carburetion
Electronic fuel injection and control
Exhaust gas recirculation r
Air injection at exhaust ports
Variable air injection
Oxidizing catalytic converter
Reducing catalytic converter
Three-way catalytic converter with 0_ sensor
Lean thermal reactor
Rich thermal reactor
Oxidizing catalyst bypass system
Evaporative control
Emission test
Designation
El
FC
QHI
1C
FIC
EFIC
EfiR
AI
AI/CAI
OC
RC
OC/RC+OS
LTR
RTR
OCBP
EC
ET
3-22
-------
3.4.2.1 Electronic Ignition (El)
Chrysler Corporation, in 1972, offered electronic ignition as an
optional feature at a cost of $34. The introduction of this feature as a
standard item should reduce its cost to the customer. It is estimated that
savings will be in the order to 25-50 percent resulting in the following
costs: (L) = $15, A = $20, H = $25.
Although electronic ignition is expected to have a higher initial
cost, net savings in maintenance costs are anticipated. Distributor points
do not have to be replaced and less frequent checks of timing and spark plug
wires will have to be made. The maintenance cost savings resulting from
electronic ignition together with the use of unleaded gas are estimated to
amount to $60 over 50,000 miles. ^ The part of the savings attributable to the
unleaded gas cannot be readily identified.
3.4.2.2 Fast Choke (FC)
This item is estimated to cost $5 for light duty vehicles by a
number of reference sources. ' ' There is no evidence that the same
device cannot be used on medium duty vehicles. This cost is, therefore, used
here. There are no incremental maintenance costs with the fast choke.
3.4.2.3 Quick Heat Intake Manifold (QHI)
The cost of this device is estimated to be the same, $5, as that of
the fast choke (FC) noted in the previous Section 3.4.2.2.
3.4.2.4 Improved Carburetion (1C)
Improved carburetion provides for altitude compensation and better
air/fuel ratio control. We estimate the incremental costs of these modifications
to be L = $5, A = $10 and H = $15.
3-23
-------
Reference'(5) indicates an incremental maintenance cost of $15 over
50,000 miles for these features, which cost is used here.
3.4.2.5 Advanced Carburetion (FIC)
This device is not sufficiently defined to provide a basis for an
independent cost estimate. In the absence of data, the cost assigned to
advanced carburetion is 3 times the cost of the improved carburetor (1C), $45,
both for the initial sticker price and the maintenance cost.
3.4.2.6 Electronic Fuel Injection and Control (EFIC)
Reference (2) indicates an initial cost of $98 for this device.
Telcons with Volkswagen of America and Bendix provided estimates of
$100-$200 for this device. The latter, however, apparently do not account
for credits for items which are replaced by this device. The costs employed
are L = $75, A = $100, and H = $125.
Nozzles are estimated to require replacement every 50,000 miles.
(2)
Nozzle costs are $2 each. Assuming one hour of labor at $12/hr. is required
for nozzle replacement, this yields a cost of $24 for 16 and $28 for V8 engines,
3.4.2.7 Exhaust Gas Recirculation (ERG)
(8)
Discussion with Ford Motor Co. indicated that essentially the
same device is used on all present engines. It is assumed that the same
device can be used on medium duty vehicles. Estimated costs in References
(9)
(2), (3) and (4) provide a range $25-$47. Another report shows a cost of
$7.40. The costs used in this study are L = $20, A = $30 and H = $40.
Maintenance EGR costs are based on Reference (9). They consist of
a filter change every 10,000 miles equivalent to an oil filter change. This
cost is estimated to be $4.
3-24
-------
3.4.2.8 Air Injection (AI)
References (2), (3) and (4) show a range of $29-$46 for air injection
with an average cost of $38. There may be a small variation in the size of
air pumps required for the different size engines. We do not believe that
this change will have a significant impact on costs. We assume that the $38
cost is for a V8 engine. The cost of air injection for the 16 engine
is estimated to be $36.
There is no existing data for AI maintenance costs. It is
assumed that some maintenance and parts are required every 25,000 miles
and that one half hour of labor is required for this maintenance action.
Costs of $9 and $10, respectively, are included for 16 and V8 engines.
3.4.2.9 Variable Air Injection (AI/CAI)
This device is similar to that described in Section 3.4.2.8 except
for the addition of 1 valve costed at $1. This results in a cost of $39 for
V8 engines and $37 for 16 engines. The maintenance cost is assumed to be the
same as that for AI.
3.4.2.10 Oxidizing, Reducing and Three-Way Catalytic Converters (OC,RC,OC/RC)
We cannot discern any differences between the two types of converters
which should result in differences in costs between the two, assuming that
both are the same size. This conclusion is supported by the Aerospace Corp.
report in which it is stated that the manufacture of noble and base metal
catalysts would result in the same costs.
Experiments are in progress in which large volume catalytic
converters (catalyst bed = engine CID) are tested on medium duty vehicles.
Estimated converter costs as a function of catalyst bed volume, based on
verbal data obtained from U.O.P. ' is shown in Figure 3.11.
3-25
-------
$ 120
100
80
60
00
8
40
20
WCRPC = CSP - WHOLESALE COST; INITIAL STICKER PRICE
PRPCBj - REPLACEMENT COST OF CATALYST BED (INSTALLED)
CRPCj - REPLACEMENT COST OF COMPLETE CONVERTER (INSTALLED)
50
100 150 200
CATALYST BED VOL. IN3
250
Figure 3.11 CATALYTIC CONVERTER COST
3-26
-------
The UOP data provided the basis for estimating the replacement
cost (installed) for catalytic converters, labeled CRPCj in Fig. 3.11. This
cost was assumed to include 1/2 hour of labor at $12/hr. Thus, the replace-
ment cost of the converter itself is CRPCj-$6. The wholesale cost (WCRPC) is
estimated to be .7(CRPC -$6). Automobile manufacturers will undoubtedly pay
less than WCRPC but will incur additional costs for receiving, installation
and inspection. Thus, the initial sticker price CSP is assumed to be the
same as the wholesale price.
It is estimated that 75% of the catalytic converter cost is for
the catalyst bed and the remainder for the container. Thus, the cost to the
customer for a replacement of the catalyst bed (PRPCB.) is .75 (CRPCT-$6) + $6
again assuming that this maintenance action involves one half hour of labor.
The three-way catalyst additionally includes an 0- sensor with
an initial cost of $7. The sensor must be replaced every 25,000 miles at an
estimated cost of $13 which includes 1/2 hour of labor.
3.4.2.11 Lean and Rich Thermal Reactors (LTR § RTR)
Thermal reactors are estimated to cost 75% of the cost of
comparably sized catalytic converters and are assumed to last the life of the
vehicle.
A comparison of thermal reactor and catalytic converter sticker
price costs derived herein with other published source costs is shown in
Fig. 3,12. The other source data do not specify the specific engine size for
which the devices are intended. The Calspan data is based on a 350 CID engine.
3.4.2.12 Oxidizing Catalyst Bypass
This device includes a thermocouple, a valve, a solenoid and some
pipes. The estimated sticker prices of this device are L = $5, A = $10 and
H = $15.
3-27
-------
$140
130
120
110
100
90
80
v> 70
O
u
60
50
40
30
20
10
<
«
<
J
>
<
M
^
k.
*
,
>
»
i ^
'
(o
uu
-- -
<
1
>
>
t.
'"
)
\
CALSPAN EST
ST ESTIMATES
ENGLEHARD, E
NAS, RTI & SR
\
^
<
MATES)
350 Cl
SSO, AE
ESTIM/l
>
!
•
>
3 ENGIIN
ROSPAC
TES
(
<
k
>
>
>
<
<
c
i
^ ,
E, DUPONT, ETHYL CO
•
•
>
RP.;
k
HC
CO
DUAL
BED
LTR
RTR
CATALYTIC CONVERTER/THERMAL REACTOR
LOW
GRADE
Figure 3.12 CATALYTIC CONVERTER & THERMAL REACTOR COST ESTIMATES-
350 CID ENGINE
3-28
-------
The annual maintenance and inspection cost of this device based
on 10,000 miles/year travel is $5. '
3.4.2.13 Evaporative Control
The evaporative control system consists of a domed tank vapor
separator and carbon canister. The sticker price •* is L = $13, A = $14
and H = $15. The carbon canister is estimated to require replacement after
25,000 miles at a cost of $12.50.
3.4.2.14 Emission Test
The emission test end-of-assembly line costs are assumed to be the
same as the current California procedure (i.e. 2% CVS, 25% 7-Mode and 75% idle
and functional checks). These costs ' are included as L =$6, A =$7 and H =$8.
Recurring inspection and test costs are $3 per year.
3-29
-------
3.4.3 Incremental Diesel Engine Costs
The use of diesel engines is considered to meet emission standards,
The differences between the initial purchase price of the diesel vs. the
baseline spark ignition engines represent a part of the cost of meeting the
standard.
Initially, the cost of a baseline spark ignition engine must be
determined. The difficulty here is to establish the cost for any one
particular engine. Once this is accomplished, the determination of the costs
of other engines is straightforward. This is because manufacturers quote
price differentials for different sized engines. For example, the vehicle
base price may include a small V8. Alternative prices are quoted for the
same vehicle powered by a smaller 16 or larger V8 engines.
The cost differences associated with different engine sizes are
independent of vehicle type. Discussions with truck dealers have shown that
the cost difference between a small and large V8 is the same for a pick-up
truck as for a Van; although the base sticker prices of the two vehicles may
differ significantly.
An initial engine cost was derived as follows. We selected the
smallest and next largest 16 engines which are installed in trucks in the
6-14,000 Ibs. GVW category. The difference in costs between the engines
was then divided by their difference in HP. This cost/HP was then used to
compute the cost of the smaller 16.
The resultant costs for engines with displacements from 225-500
in are presented in Figure 3.13.
The discussion following on diesel engines is based largely on
discussions held with Mr. Neville Hartwell, Perkins Engine Co., on
March 16, 1973.
3-30
-------
$1000i
900
800
700
o
V)
O
o
111
o
E
Q.
600
500
400
300
200
100
100
200
300
400
16-*-
-*-V8
ENGINE CID
500
Figure 3.13 ESTIMATED COSTS OF CURRENT SPARK IGNITION ENGINES
.3- 31
-------
Generally, current diesel engines are not designed for medium
duty vehicles. New or modified designs of present engines with matched
torque converters and automatic transmissions would have to be developed
to meet the requirements of the medium duty vehicles. Lead times of 8-10
years would be needed to reach full production for a family of engines.
This lead time could be reduced to about 5 years if the objective was to
develop one engine which may have widespread applicability in medium duty
vehicles.
These "new" diesel engines, if produced within present production
capacities are estimated to cost twice as much as spark ignition engines with
comparable CID's. Expanded production, i.e. equivalent to that of the current
spark ignition engines, could result in a cost reduction of 25-30 percent.
Diesel engine costs, based on the premises of existing and
expanded production facilities are shown in Figure 3.14.
Figure 3.15 shows the differences between the costs of spark
ignition engines shown in Figure 3.13 and the high and low diesel engine costs
presented in Figure 3.14. The middle line in Fig. 3.15 is based on the
midpoints of the high and low diesel engine costs in Figure 3.14. For
example, the incremental, anticipated sticker price for a 350 CID diesel
engine is $355.
3.4.3.1 Other Diesel Engine Associated Costs
The only emission control device considered with the diesel
engine is EGR. Its cost is assumed to be the same as that for the spark
ignition engines, i.e. L = $20, A = $30, and 11 = $40. Additionally, a $100
incremental cost is charged to all diesel powered vehicles to cover structural
changes and improved brakes which may be required because of the higher
weight of diesel engines. Finally, the cost of power steering, $125, is
added to all diesel powered vehicles with engine displacements of less than
3-32
-------
$ 1500
1400
1300
1200
nor
1000
900
800
700
600
500
400
300
200
100
COSTS BASED ON
PRESENT PRODUCTION
FACILITIES
COSTS BASED ON
EXPANDED PRODUCTION
FACILITIES
100
200
300
ENGINE CID
400
500
Figure3.14 ESTIMATED COSTS OF DIESEL ENGINES
3-3.3
-------
S 600
500
400
-------
350 cu. in. It is assumed that all vehicles, gasoline or diesel, equipped
with 350 CID or larger engines, normally would be delivered with power
steering.
Historically, diesel engines have exhibited lower maintenance
costs than comparable gasoline engines. The new type diesel engines we are
considering represent an unknown item. Consequently, we assign no maintenance
cost savings to the diesel engine compared to the baseline spark ignition
engine. This represents a conservative approach biased in favor of the spark
ignition engine. The diesel.engine, as a new concept, however, is the
challenger in this case. Its credibility as a substitute engine will be
enhanced if it can be proved to be more cost-effective despite this bias.
The only incremental maintenance cost shown for the diesel engine
is that associated with its EGR. This cost is the same as the EGR maintenance
cost described in Section 3.4.2.7.
3-35
-------
3.5 Emission Control System Costs
Eight emission control systems for use with spark ignition engines
are developed and described in the Part A Technical Analysis. The costs of
these systems and the incremental costs incurred with diesel engines are
presented in this section.
Separate costs are first shown for each of the three major cost
categories considered.
1. Initial or sticker prices to customers
2. Incremental maintenance costs
3. Incremental operating costs.
The last category reflects changes in fuel consumption resulting from the
implementation of the systems. The costs are based on the cost factors
described in the preceding Section 3.4, The total costs are the sum of the
three costs based on 50,000 miles or 5 years of vehicle usage.*
Costs are shown for three representative engine sizes employed in
medium duty vehicles. They are: 16-300 CID, V8-350 CID and V8-454 CID.
3.5.1 Sticker Prices of Emission Control Systems and Diesel Engines
Estimated sticker price increases for the eight emission control
systems are shown in Table 3.6, Low (L), projected anticipated (A) and high (H)
costs are indicated for each system. The initial sticker prices range from
about $100 to $400; the higher cost systems are those which include catalytic
converters.
Certification costs are not included. These costs are highly uncertain at this
time and may vary considerably between manufacturers. This problem is addressed
in Section 3.7.1.
3-36
-------
TABLE 3.6
STICKER PRICES OF EMISSION CONTROL SYSTEMS
SYS. NO. SYSTEM 16-300 V8-350 V8-454
1
2
3
4
5
6
7
8
L
A
H
L
A
H
L
A
H
L
A
H
L
A
11
L
A
H
L
A
H
L
A
H
EI+FC+AI+EGR+EC+ET $ 95
112
129
EI+AI+EGR+IC+QHI+EC+ET 100
122
144
EI+AI+EGR+IC+QHI+OCBP+ 154
OC+EC+ET 195
237
EI+EGR+IOqHI+OC+RC+ 204
' OCBP+AI/CAT+EC+ET 259
306
EI+EGR+OC/RC+EFIC+EC+ET 185
241
298
EI+EGR+IC+QHI+LTR+EC+ET 106
139
172
EI+FC+AI+EGR+RTR+EC+ET 137
165
193
EI+AI+EGR+QHI+FIC+EC+ET 110
142
174
$ 97
114
131
102
124
146
161
204
253
236
295
356
190
248
307
111
145
180
144
173
203
112
144
176
$ 97
114
131
102
124
146
171
219
268
255
325
396
200
263
327
120
159
197
153
186
220
112
144
176
3-37
-------
Control systems Nos. 1, 2 and 8 are insensitive to engine
displacement. In the remaining systems, the relatively large variations in
costs both as a function of engine displacement and between low and high
costs are due to the assumptions made concerning the sizes of the catalytic
converters and thermal reactors. The values employed are shown below:
OR, RC 5 OC/RC L = 40% CID A = 60% CID H = 80% CID
LTR $ RTR L = 50% CID A = 70% CID H = 90% CID
System Nos. 3 and 5 use one OC or OC/RC, respectively, for both the 16 and V8
engine configurations. System No. 4 includes one OC and one RC for the 16
engine. The V8 engines have one OC and 2 RC's, one in each bank.
The incremental sticker prices incurred with diesel engines are
shown in Table 3.7. The major portion of the costs consists of the initial
higher price of diesel engines compared to current spark ignition engines.
The apparent cost discrepancy between the 16-300 and V8 engines is due to the
fact that power steering is included as mandatory with the diesel 16 whereas
the larger gasoline engines are assumed to be already provided with power
steering.
3.5.2 Maintenance Costs of Emission Control Systems and Diesel Engines
These costs are shown in Tables 3.8 and 3.9. They are incremental
costs computed for 50,000 miles or five years of vehicle operation.
The 5 year incremental maintenance costs are relatively low for the
systems which do not use catalytic converters. Two types of maintenance costs
are shown for the three catalytic converter systems, Nos. 3, 4 and 5. The
first cost includes one replacement of the entire catalytic converter(s) ; the
second replacement of the catalyst bed(s) only. Either choice has a
significant impact on maintenance costs involving substantial costs to the
customer.
3-38
-------
TABLE 3.7
STICKER PRICES OF DIESEL ENGINE SYSTEMS
ENGINE SIZE
SYSTEM
ADIESEL ENGINE
A DIESEL ENGINE COST+EGR+ET+MISC.
L
A
H
L
A
H
300^ in3
$ 431
532
633
451
562
673
350 in3
$ 341
462
573
361
492
613
454 in3
$ 436
602
733
456
632
773
1. 300 in Engine included Power Steering Cost ($125)
2. Emission Test (ET) cost is (L)$6, (A)$7, (H)$8
3. MISC includes $100 cost increment for added weight and design
3-39
-------
TABLE 3.8
INCREMENTAL MAINTENANCE COSTS (50,000 MI.)
SYS. NO.
SYSTEM
16-300
V8-350
V8-454
1
2
3
4
5
6
7
8
L
A
H
L
A
I!
L
A
H
L
A
H
L
A
H
L
A
H
L
A
H
L
A
EI+FC+AI+EGR+
EC+ET
EI+AI+ECR+IC+
QHI+EC+ET
EI+AI+EGR+IC+
QHI+OC+EC+ET
+OCBP
EI+EGR-t-IC+QHI +
OC+RC+AI/CAI+
EC+ET+OCBP
EI+EGR+OC/RC+
EFIC+EC+ET
EI+EGR+IC+QHI
LTR+EC+ET
EI+FC+AI+EGR
+RTR+EC+ET
EI+AI+EGR+QHI
EC+ET+FIC
$ 9
9
9
24
24
24
124/106.5
146.5/121.5
166.5/136
199/164
244/194
274/224
111.5/94
134/109
154/124
15
15
15
9
9
9
54
54
$ 10
10
10
25
25
25
132.5/112.5
157.5/130
180/147.5
250/202.5
300/237.5
345/272.5
- 1 23/103
148/120.5
170.5/138
15
15
15
10
10
10
55
55
$ 10
10
10
25
25
25
147.5/122.5
177.5/145.5
207.5/170
280/225
340/270.5
400/317.5
138/113
168/135.5
198/160.5
15
15
15
10
10
10
55
55
Note: With 1 replacement of converter(s)/with 1 replacement of converter
element(s).
3-40
-------
TABLE 3.9
DIESEL MAINT. COSTS (50,000 MI.)
DIESEL
ET
TOTAL
DIESEL W EGR
EGR
ET
TOTAL
$ LOW
J_5
15
20
II
35
$ ANTICIPATED
J_5
15
20
ii
35
$ HIGH
!§.
15
20
II
35
3-41
-------
The incremental diesel engine maintenance costs are relatively
small. In fact, they will be probably considerably lower than indicated.
Present experience shows that diesel engines are inherently more reliable and
require less maintenance than comparable gasoline engines. This factor is not
considered in the determination of the diesel engine maintenance costs.
3.5.3 Incremental Fuel Costs of Emission Control Systems and Diesel
Engines
Incremental fuel costs incurred due to emission control systems
are listed in Table 3.10. Baseline fuel consumptions are based on representative
inertial weights of vehicles in which the various size engines may be installed.
Fuel savings resulting from the use of diesel engines are contained in Table
3.11. All fuels are estimated to cost $0.45 per gallon. Inquiries addressed
to local dealers indicated no significant differences in retail prices be-
tween gasoline and diesel fuels.
3.5.4 Total Costs
The total system costs shown in Tables 3.12 and 3.13 are the sum of:
STICKER PRICE + INCREMENTAL MAINT. COST •»• INCREMENTAL FUEL COST
The total costs are for 50,000 miles of vehicle operation. They include one
replacement of catalytic converters for those systems which employ these
devices.
A range of inertial weights is included here to correspond to the
engine sizes considered. Note that different inertial weights are used in the
analysis conducted with the AMTEC model.
3-42
-------
TABLE 3.10
INCREMENTAL FUEL COSTS (50,000 MI.)
ENGINES
TESTED INERTIAL WEIGHT
BASELINE FUEL USAGE (MPG)
SYSTEM NUMBER
L
A
II
L
A
I!
L
A
H
L
A
H
L
A
11
L
A
I!
L
A
II
L
A
H
0
-4
-7
•10
-3.
-5
-7
-10
-12
•14
-10
-12
-14
-1
-3
-5
-6
-8
-10
-20
-25
-30
-1
_ •?
-5
16-300
6000 Ibs.
11.5
$ 80
147
217
- 59
102
147
217
266
317
217
266
317
20
59
102
123
168
217
489
651
837
20
59
102
V8-350
9000 Ibs
7.3
$ 123
225>
333
90
156
225
333
408
486
333
408
486
30
90
156
189
258
333
750
999
1284
30
90
156
V8-454
11,000 Ibs.
5.5
$ 168
307
454
123
213-
307
454
556
663
454
556
663
41
123
213
258
352
454
1023
1362
1751
41
123
213
3-43
-------
TABLE 3.11
DIESEL OPERATING COST - (50,000 MI.)
DIESEL WITHOUT EGR
BASELINE FUEL USAGE (MPG)
DIESEL
DIESEL WITH EGR
BASELINE FUEL USAGE (MPG)
DIESEL
300 in3
17.3
$-656
17
$-634
350 in'
11
$-1037
10.7
$-979
454 in'
8.3
$-1380
8.1
$-1313
Note :
- = Savings
3-44
-------
TABLE 3.12
TOTAL SYSTEM COST - (50,000 MI.)
ENGINES
INERTIAL WEIGHT
SYSTEM NUMBER
L
A
H
L
A
H
L
A
H
L
A
H
L
A
H
L
A
H
L
A
H
L
A
(I
16-300
6000 LBS.
$ 184
268
355
183
248
315
495/478
608/583
721/691
620/585
769/719
897/847
317/229
434/409
554/524
244
322
404
635
825
1039
184
255
330
V8-350
9000 LBS.
$ 230
349
474
217
305
396
627/607
770/742
919/887
819/772
1003/941
1187/1115
343/323
486/459
634/601
315
418
528
904
1182
1497
197
289
387
V8-454
11,000 LBS
$ 275
431
595
250
362
478
773/748
953/921
1139/1101
989/934
1221/1152
1459/1377
379/354
554/522
738/701
393
525
666
1186
1558
1981
208
322
444
Note: With 1 replacement of converter(s)/with 1 replacement of converter
element(s).
. 3-45
-------
TABLE 3.13
DIESEL ENGINE TOTAL SYSTEM COSTS
(50,000 MI.)
ENGINE SIZES
300 in3 350 in'3 454 in'3
L $ - 210 $-681 $-929
Diesel A - 109 -560 -763
H - 8 -449 -632
L - 148 -583 -822
Diesel with EGR A - 37 -452 -646
H 74 -331 -505
Note:
- = Savings
3-46
-------
3.6 Emission Control System Lead Times
Estimated lead times for the eight emission control systems are
shown in Figure 3.16. The lead time categories considered are:
1. Initial design
2. Prototype development
3. Prototype test and evaluation
4. Certification
5. Design review
6. Production facility planning, construction and tooling
7. Preproduction
8. Initial production
The presented lead times are predicated on a sequential progression
of activities culminating in the initial production of a system. For example,
it is assumed that work on new production facilities (where required) is not
initiated until after system certification. An earlier decision to proceed
together with the attendent commitment of necessary funds could result in
appreciably reducing some of the indicated lead times. This is particularly
true with regard to the systems which include catalytic converters on thermal
reactors.
The eight emission control systems are presently in varying stages
of development. For example, development of system No. 1 is essentially
complete. In contrast, the advanced carburetion system employed in System No. 8
is best designated as a concept at this time.
Most systems require the development of more than one new device.
It is assumed that parallel efforts are conducted in these instances and the
time periods shown reflect that device deemed to have the longest lead time.
3-47
-------
SYSTEM NO. 1
1
234
P 7
10
34
45
45
1. SYSTEM DESIGN
2. PROTOTYPE DEV.
3. PROTOTYPE TEST & EVAL.
4. CERTIFICATION
5. DESIGN REVIEW
6. PROD. FAC. & TOOL.
7. PREPRODUCTION
8. INITIAL PRODUCTION
20
30 40
MONTHS
50
60
70
Figure 3.16 ESTIMATED SYSTEM LEAD TIMES
-------
The devices which are believed to require the longest lead times
are the catalytic converters -- approximately 24 months. A detailed discussion
of the derivation of this lead time is contained in Appendix B.
Generally 2 1/2 to 4 months are allocated for prototype test and
evaluation, 6 months for certification and 1-2 months for design review
at which time the decision to proceed with production is made.
Lead time category No. 6, concerned with production facilities
and tooling varies considerably between the systems. The required activities
may vary here from minor to major production line changes to the construction
of entirely new facilities. The time allocated for these activities vary
from 6 months to 2 years.
Three months are allotted for preproduction and one additional
month reach initial mass production.
Systems Nos. 1 and 2 could become available within 2 years. For
example, General Motors and Chrysler Corporation indicate lead times of
25-28 months for carburetors similar to the improved carburetors included in
Systems Nos. 1 and 2. Systems employing catalytic converters (3, 4 and 5)
are shown to have lead times of 4-6 years; thermal reactor systems about
4 years.
Discussions with Perkins Engine Co. personnel indicated that
large-scale production of a family of diesel engines could not be achieved
before 1980-1982. Production of one engine with wide applicability, such as a
350 Gin diesel engine, given the necessary priority, may be possible by
1978-1979.
3-49
-------
3.7 System Comparison
Table 3.14 lists the emission control systems and their estimated
effectiveness (i.e. emission reduction) ranked in the order of ascending costs.
The comparison is for a V8-350 CID spark ignition engine.
Based on effectiveness, cost and lead times, systems Nos. 1, 4 and
7 do not appear to offer any benefits which cannot be achieved with other
systems more efficiently and economically. System No. 2 is cheaper and more
effective than No. 1 and becomes available at approximately the same time.
System No. 5 matches the effectiveness of No. 4 at less than one half its cost.
The difference in lead times between the systems is less than 1 year.
System No. 7 is characterized by high costs due mainly to the large fuel
penalty associated with it. System No. 5 can provide approximately the same
benefits at a much lower cost, albeit one year later.
Comparable data for the two diesel engine configurations, system
No. ID with out EGR and No. 2D with EGR, are presented in Table 3.15. Both
systems offer more than 90% reductions in HC and CO, but only 42-67 reductions
of baseline NO emissions. The total costs of both diesel engine systems
A
are significantly lower than that of the baseline engine and provide significant
fuel savings. It must be recognized, however, that large-scale production of
a family of diesel engines for medium duty vehicles is 8-10 years in the future.
As described in the introductory section 3.1, the emission control
systems considered offer basically three choices or routes for the reduction
of emissions. These are designated as: 1. improved carburetion, 2. catalytic
converters and 3. thermal reactors. This represents somewhat of an oversimpli-
fication since the improved carburetion (1C) of system No. 2 appears in systems
No. 3 and 6 as well. The latter two systems also include an oxidizing catalytic
converter and a thermal reactor,respectively.
3-50
-------
TABLE 3.14
EMISSION CONTROL SYSTEM COMPARISON: V8-350 ENGINE
( 9000 Ibs. inertial weight)
AVERAGE
SYS. NO. EMISSION REDUCTION TOTAL COSTS (SO,000 MI.) A FUEL USED (GAL.)
% % % RANGE ANTICIPATED
8
2
1
6
5
3
4
7
HC
60
35
-30
50
82
82
82
92
CO
70
45
5
65
85
85
85
65
NOX
65
40
35
62
90
40
90
83
L
197
. 217
230
315
323
343
607
627
772
819
904
H
387
396
474
528
601*
634^
887*
919"
1115*
1187
1497
A
289
305
349
418
459*
486
7702
ioor
1182
RANGE
L-ll
67-347
200-500
273-740
420-740
67-347
740-1080
740-1080
1667-2853
ANTICIPATED
A
200
347
500
573
200
907
907
2220
1 .
with one (1) replacement of catalyst element
2
with one (1) replacement of complete converter
-------
TABLE 3.15
EMISSION CONTROL SYSTEM COMPARISON - DIESEL 350 CID
(9000 Ibs. inertial weight)
SYS. NO. EMISSION REDUCTION TOTAL COST FUEL SAVINGS
% % % (50,000 mi) GALLONS
HC CO NOX
ID 96 95 42 $-560 2304
2D 96 95 67 $-452 2176
Note:
- = Savings
3-52
-------
Emission control through improved carburetion can be achieved
largely using existing production facilities. The other two choices will
require extensive capital expenditures for new production facilities for the
manufacture of catalytic converters and thermal reactors.
The three approaches are outlined in Table 3.16. All are initiated
with the introduction of system No. 2 which can be made available within 2
years. The improved carburetion and thermal reactor approaches result in
approximately equal effectiveness. The use of catalytic, converters potentially
offer the greatest reduction of pollutant emissions. The most advanced
catalytic converter system (No. 5) emits about one half of the HC and CO and
one third of NO of the best postulated advanced carburetion system (No. 8).
J\
Tables 3.17, 3.18, 3.19 and 3.20 show the effectiveness and costs
of the various approaches considered. The data are presented for a 350 CID
engine for each of the 4 major vehicle categories. Effectiveness is expressed
in terms of grams/mile of residual emissions. The costs are for 50,000 miles
of operation and include the initial sticker price, incremental maintenance
and fuel costs.
The diesel engine appears to offer the best long term solution of
the emission problem. It provides the best control of HC and CO emissions of
the systems considered. Its control of NO emissions is roughly comparable to
what can be achieved with the best "improved carburetion" systems but not as
good as the most advanced catalytic converter system No. 5.
Diesel engines provide economy in operations far superior to any
of the other alternatives considered. Their cost advantage derives from
their significantly lower fuel consumption which more than off-sets the
higher initial sticker prices of diesel-powered vehicles.
The various emission control approaches described earlier were
examined with the AMTEC model. The cases considered are listed in Table 3.21.
3-53
-------
I
on
TABLE 3.16
System Comparison V8 - 350 Engine
Lead Time Improved Carburetion Catalytic Converter Thermal Reactor
(Years) Sys. % Reduction Sys. % Reduction Sys.% Reduction
HC CO NO HC CO NO HC CO NO
XX 3
1 (2) 35 45 40 (2) 35 45 40 (2) 35 45 40
(8) 60 70 65 (3) 82 85 40 (6) 50 65 62
(5) 82 84 90
-------
TABLE 3.17
IMPROVED CARBURETION EFFECTIVENESS AND COSTS - 350 CID ENGINE
(50,000 MILES)
VEHICLE
TYPE
INERT IAI, WT.
LBS.
RESIDUAL EMISSIONS GM/MI
HC CO N0%,
TOTAL COSTS
.(ANTICIPATED)
System No. 2
Truck
Truck
Motor Home
Motor Home
6,000
10,000
8,000
12,000
3.5
4.9
5.3
12.5
33.0
49.5
56.7
110.0
4.6
7.1
7.2
16.2
$ 266
323
297
354
System No. 8
Truck
Truck
Motor Home
Motor Home
6,000
10,000
8,000
12,000
2.1
3.0
3.2
7.7
18.0
27.0
30.9
60.0
2.7
4.1
4.2
9.5
268
301
286
320
Note:
Trucks are assumed to be lightly loaded. The inertial weights of the motor
homes are selected at the midpoints of the 6-10,000 and 10-14,000 Ibs.
GVW categories.
3-55
-------
TABLE 3.18
THERMAL REACTOR EFFECTIVENESS AND COSTS - 350 CID ENGINE
(50,000 MILES)
VEHICLE
TYPE
INERTIAL WT.
LBS.
RESIDUAL EMISSIONS GM/MI
HC CO NO.,
TOTAL COSTS
(ANTICIPATED)
System No. 2
Truck
Truck
Motor Home
Motor Home
6,000
10,000
8,000
12,000
3.5
4.9
5.3
12.5
33.0
49.5
56.7
110.0
4.6
7.1
7.2
16.2
$ 266
323
297
354
System No. 6
Truck
Truck
Motor Home
Motor Home
6,000
10,000
8,000
12,000
2.7
3.8
4.1
9.7
21.0
31.5
36.1
70.0
2.9
4.5
4.6
10.3
353
447
404
500
Note:
Ibid Table 3.17.
3-56
-------
TABLE 3.19
CATALYTIC CONVERTER EFFECTIVENESS AND COSTS - 350 CID ENGINE
(50,000 MILES)
VEHICLE
TYPE
System No. 2
System No. 3
Truck
Truck
Motor Home
Motor Home
System No. 5
Truck
Truck
Motor Home
Motor Home
INERTIAL WT.
LBS.
RESIDUAL EMISSIONS GM/MI
HC CO NO,,
6,000
10,000
8,000
12,000
6,000
10,000
8,000
12,000
TOTAL COSTS
(ANTICIPATED)
Truck
Truck
Motor Home
Motor Home
6,000
10,000
8,000
12,000
3.5
4.9
5.3
12.5
33.0
49.5
56.7
110.0
4.6
7.1
7.2
16.2
$ 266
323
297
354
Notes: For systems Nos. 3
Ibid Table 3.17
1.0
1.4
1.5
3.5
9.0
13.5
15.5
30.0
4.6
7.1
7.2
16.2
582/610
701/729
646/674
769/797
1.0
1.4
1.5
3.5
9.6
14.4
16.5
32.0
.8
1.2
1.2
2.7
438/465
471/498
456/483
490/517
With one replacement of the catalyst element/
With one replacement of catalytic converter.
3-57
-------
TABLE 3.20
DIESEL ENGINE EFFECTIVENESS AND COSTS - 350 CID ENGINE
(50,000 MI.)
Diesel #1
Truck
Truck
Motor Home
Motor Home
INERTIAL WT.
LBS.
6,000
10,000
8,000
12,000
RESIDUAL EMISSIONS GM/MI
HC CO NOX
,2
,3
,3
,7
2.7
4.1
4.4
8.3
4.4
6.7
6.7
15.3
TOTAL COSTS
(ANTICIPATED)
$-290
-669
-507
-908
Diesel #2
Truck
Truck
Motor Home
Motor Home
6,000
10,000
8,000
12,000
,2
3
,3
,7
2.7
4.1
4.4
8.3
2,5
3.8
3.8
8.7
-211
-576
-411
-800
Note:
Ibid Table 3.17.
3-58
-------
Run No.
I
II
III
IV
V
VI
TABLE 3.21
ALTERNATIVE EMISSION CONTROL APPROACHES
System No.
2 • '
8
2
6
2
3
. 5
2
8
Diesel + EGR
2
3
5
Diesel * EGR
Year Introduced
1975
1975
1978
1975
1977
1975
1977
1978
1975
1978
1978
1975
1977
1978 :
: . 1978
Phase-in of Diesel Engines (% of Annual Sales) ••
Trucks 6000 Ibs. GVW: 5%-1978, 10%-1979, 25%-1980-1989
Trucks 10,000 Ibs. GVW: 10%-1978, 20%-1979, 35%-1980, 50%-1981, 65%-1981-1989
Motor Homes 8000 Ibs. GVW: 5%-1978, 10%-1979, 25%-1980, 50%-1981-1989
'v
Motor Homes 12,000 Ibs. GVW: 10%-1978, 20%-1979, 35%-1980, 50%-1981,
65%-1982-1989
3-59
-------
The results are presented in Table 3.22. The data shown for each approach
include:
1. Omission reductions in specified years as a percent of
baseline emissions
2. Fuel penalty/(savings) expressed as a percent of the baseline
fuel consumption
3. Total annual low and high costs; and
4. Anticipated costs over the 15 year period.
Baseline emissions are the quantities of pollutants which would
be emitted in the absence of control systems. The greater effectiveness of
the systems over the years result from the fact that vehicles equipped with
control devices comprise an increasing segment of the total medium duty
vehicle population. The 1989 emission reduction percentages are very close
to the greatest reductions that can be achieved with the systems.
The annual costs are successively higher for each of the four
years considered for the approaches which utilize gasoline engines equipped
with emission control systems. Approaches which include diesel engines show
declining costs in the years following the introduction of these engines.
The declining costs are due to the considerably greater*fuel economy of these
engines.
The annual costs are close to their levelling off points by 1989
for the specified mix of vehicles. This is indicated by the fact that emission
reductions are almost equal to the greatest reduction possible with the
control systems.
The approaches which use only gasoline engines with emission
control systems result in fuel penalties ranging from 3-8 percent. The
inclusion of diesel engines result in fuel savings of 6-7 percent. These
percentages are relative to the fuel consumption which would have occurred if
the vehicle population had been equipped with the baseline gasoline engine
without emission control systems throughout the period.
3-60
-------
TABLE 3.22
Effectiveness and Annual Costs of Emission Control Approaches
1975
1980
1985
1989
Sys. No. 2
Emission Reductions HC/CO/NO (%)
Fuel Penalty/(Savings) (%) X
Costs Low - High ($M)
Sys. Nos. 2 & 8
Emission Reductions HC/CO/NO (%)
Fuel Penalty/(Savings) (%) X
Costs Low - High ($M)
Sys. Nos. 2 & 6
Emission Reductions HC/CO/NO (%)
Fuel Penalty/(Savings) (%) X.
Costs Low - High ($M)
Sys. Nos. 2, 3, & 5
Emission Reductions HC/CO/NO (%)
Fuel Penalty/(Savings) (%) X
Costs Low - High ($M)
Sys. Nos. 2 & 8, with Diesel + EGR
Emission Reductions HC/CO/NO (%)
Fuel Penalty/(Savings) (%) X
Costs Low - High ($M)
Sys. Nos. 2, 3 & 5 with Diesel + EGR
Emission Reductions HC/CO/NO (%)
Fuel Penalty/(Savings) (%) X
Costs Low - High ($M)
4/5/11
1
88-123
4/5/11
1
88-123
4/5/11
1
88-123
4/5/11
1
88-123
4/5/11
1
88-123
4/5/11
1
88-123
23/27/27
3
189-253
30/36/36
3
181-259
28/36/38
5
238-337
42/45/40
4
286-423
33/38/36
0
184-294
; 43/46/38
2
; 269-425
31/40/36
5
290-384
50/59/55
3
249-352
43/56/55
7
394-541
69/72/71
4
359-530
64/69/56
(A)
59-161
75/76/62
(4)
141-291
. 34/44/39
5
363/478
57/67/62
3
297-418
48/63/61
8
506-689
79/72/83
3
409-605
77/81/64
(7)
(49)-39
36/88/72
(6)
32-172
Total Anticipated
Costs, 1975-1989
$ Billions
3.991
3.683
5.338
5.417
2.042
3.400
Note: ( ) denote savings . '
Total costs for systems Nos. 3 and 5 include replacement of the entire catalytic converter(s)
every 25,000 miles.
Percent emission reductions are relative to 1972 base line engine.
-------
The total anticipated incremental costs incurred over the 15 year
period by implementing the alternative approaches are shown in the last
column. These costs range from about $2 billion to $5.4 billion.
The "best" approach depends largely on the extent to which the
pollutant emissions must be reduced, particularly NO . Systems Nos. 2 and 8
provide about a 60 percent reduction of emissions by 1989 with a fuel penalty
of about 3 percent. Further reductions, without introducing diescl engines,
requires the use of catalytic converters. The cost of this approach, system
Nos. 2, 3 and 5, increases the total cost by about 50 percent - $3.7 vs. 5.4
billion.
The introduction of diesel engines equipped with EGR, in addition
to equipping the gasoline engines with system Nos. 2 and 8 offers about an
80 percent reduction of HC and CO and a 64 percent reduction of NO by 1989.
x
This reduction is achieved at the relatively low cost of $2 billion.
Concurrently annual fuel savings of about 7 percent are obtained.
Combining catalytic converter systems on'gasoline engines with
diesel-powered vehicle? provides slightly greater emission reductions. The
cost of this approach is $3.4 billion.
We conclude from the above analysis that the introduction of
diesel engines together with improved carburetion on gasoline engines provides
the most cost-effective approach. It is noted that this approach following
its implementation results in no additional costs above the baseline engines.
As shown in Table 3.22, the annual cost of this approach is about $0 by 1989.
Greater proportions of diesel engines in the vehicle mix than assumed here
would result in negative costs, i.e. savings.
3-62
-------
3.7.1 Certification Costs
It is not possible to specify a certification fleet and estimate
certification costs without precise specification and knowledge of
certification standards, engine-emission control system combinations as well
as other variables which may impact on the pollutant emissions. In the absence
of such data, a crude estimate of certification fleet costs is made based on
LDV experience. A set of conditions, as they may apply to medium duty
vehicles, is then postulated and certification fleet requirements and costs
established.
General Motor's emission test fleet for light duty vehicles in
(14)
1972 included 19 durability and 72 emission test vehicles. Total sales
of such vehicles were about 5.5 million. Information provided by F.PA^ •*
reflecting primarily G.M. experience indicated a manufacturers' certification
fleet cost of $3.41 per vehicle produced. This yields a total cost of $18.8
million and a cost of about $.2 million per test vehicle.
There is a high degree of uncertainty associated with these costs.
Initially, the costs of durability and emission data vehicles may be drastically
different with the former displaying higher costs. Additionally, the lack of
data did not permit addressing cost differentials based on manufacturer's size
and available facilities.
The total number of vehicles produced in the 6-14,000 Ibs. GVW
range is only about 5 percent of the number of light duty vehicles. The costs
of certification fleets can, therefore, become a significant sticker price
cost factor, particularly for the smaller manufacturers and for vehicle types
which are produced in relatively small quantities.
3-63
-------
3.7.1.1 Example
The 6,000-14,000 Ibs. CVW vehicles are divided into two weight
classes: 6,000-10,000 Ihs. GV1V and 10,000-14,000 Ibs. GVW. There are five
engine families within each weight class. LDV certification procedures are
assumed applicable to the medium duty vehicles.
The resultant categorizations are shown in Tables 3.23 and 3.24.
The percent of sales of engines with given CID's are based on manufacturers'
1973 sales projections.
One control system, designated A, is used on all vehicles in the
6-10,000 Ibs. GVW class. Two emission control systems, designated as A and B,
are employed on the vehicles in the 10-14,000 Ibs. GVW range.
The resultant numbers of required durability and emission test
fleet vehicles are shown at the bottom of Tables 3.23 and 3.24. A maximum of
four "B" vehicles are permitted per engine family. "C" vehicles are selected
only when an engine-emission system combination is not represented by an "A"
or "B" vehicle.
The total postulated test fleet consists of 15 durability and 38
emission test vehicles. This represents about 65 percent of GM's LDV emission
fleet. This results in a certification cost of about $10 million based on the
previously extrapolated cost of $.2 million per test vehicle.
A significant cost would be incurred by each manufacturer producing
the types and weight ranges of vehicles considered. Even assuming that the above
cost is high by a factor of two, a manufacturer whose total sales were 50,000
units would have an average cost of about $100 per vehicle sold.
3-64
-------
TABLE 3.23
CERTIFICATION FLEET REQUIREMENTS
6,000 - 10,000 GVW
ENG. FAM. CID EM. CONT. % SALES BODY TYPE
CERTIFICATION FLEET
D A B C
16-1 225-249 A
16-2 250-300 A
V8(3)-l 300-320 A
V8(3)-2 330-360 A
V8(4) 390-400 A
100 P
V/P
MS
CM/MM
100 P
V/P
MS
CH/MH
100 P
V/P
MS
CH/MH
100 P
V/P
MS
CH/MH
100 P
CH/MH
TOTALS
1 1
1 1
1
1 1 1
1
1
1 1 1
1
1
1
1 2
1
1 2
1
5 10 9
Based on 1974 LDV certification procedures
3-65
-------
TABLE 3.24
CERTIFICATION FLEET REQUIREMENTS
10,000 - 14,000 Ibs. GVW
;NG. FAM.
16.1
16-2
V8(3)-l
V8(3)-2
V8(4)
CID
225-249
225-249
250-300
250-300
300-320
300-320
330-360
330-360
390-500
390-500
EM. CONT
SYS.
Al
Bl
Al
Bl
Al
Bl
Al
Bl
Al
B,
SALES
10
90
50
50
9
91
28
72
15
85
BODY
TYPE
MS
CM/MI I
MS
CH/MI!
MS
CH/MH
MS
CH/MH
MS
CM/MU
CERTIFICATION
D
1
1
1
1
1
1
1
1
1
1
A
2
1
1
2
2
2
B
1
1
1
1
1
1
1
1
1
TOTAL
10 10
Based on 1974 LDV certification procedures.
3-66
-------
The preceding data are believed to be indicative of the magnitudes
of certification costs which may be encountered. As noted in the introductory
paragraph of section 3.7.1, the development of precise estimates requires
specific information which is not presently available. Nevertheless, the
sample analysis demonstrates that certification costs for medium duty vehicles
could have a significant impact on the total system costs; particularly for
the smaller manufacturers.
One final qualification is in order. The majority of the vehicles
which would be certified in the MDV class are presently certified using the
Heavy Duty engine procedure. A more precise analysis of MDV certification
costs would have to consider the cost increment associated with MDV certifica-
tion over present Heavy Duty certification costs.
3.7.2 Consumer Costs
The most expensive system considered results in a $.02 incremental
cost increase per mile based on 50,000 miles of travel. For most of the
systems, the cost increase due to the addition of emission control devices
is in the order of $.005 to $.01 per mile. The use of diesel engines results
in lower costs than are incurred with the baseline engines.
Discussions with local truck leasing agencies indicated that the
additional costs of emission control devices would have little or no direct
impact on consumer prices. The current pricing structure is such that a class
of vehicles which are leased at a given price include vehicles whose sticker
prices may vary considerably. A similar situation is also encountered in light
duty vehicle rentals where full-sized, low-priced vehicles are leased at the
same rates as some models of the medium-priced.
No direct relationship between sticker prices and operating costs
versus leasing rates were found. The latter are a function of many factors
important among which are demand and competition. Based on the available
3-67
-------
evidence it is concluded that the addition of emission control devices on
medium duty vehicles will not impact significantly on the user or leasing
costs of these vehicles.
Time and data restrictions did not permit alternative investiga-
tions of the impact of emission control systems on consumer costs.
3-68
-------
4. 0 REFERENCES
References for Part A
1. 1967 Census of Transportation - Vol II: Truck Inventory and
Uses, U.S. Department of Commerce, July 1970.
2. Preparation of Data Necessary for the Development of a
Heavy Duty Truck Driving Cycle for Use in Emissions Testing
Programs. Wilbur Smith and Assoc. (Interim Report) Aug. 1972.
3. Survey of Truck and Bus Operating Modes in Several Cities,
Ethyl Corporation, Final Report GR 63-24, June 1963.
4. Motor Trucks in the Metropolis, Wilbur Smith and Associates
(Commissioned by the Automobile Manufacturers Association)
Aug. 1969.
5. Zettel, R. M. and Mohr, E. A. Commercial Vehicle Taxation
in California, Institute of Transporation and Traffic Engineering,
University of California, Feb. 1972.
6. Task Progress Report, Contract No. 68-01-0463, Calspan
Corporation, March 28, 1973.
x
7. Mikus, T. and Heywood, J. B. The Automobile Gas Turbine and
Notric Oxide Emissions, 1971 Inter Society Energy Conversion
Conference, Paper No. 719012.
4-1
-------
8. Federal Certification Light Duty Vehicle Test Results for the
1972 Model Year
9. Federal Certification Light Duty Vehicle Test Results for the
1973 Model Year
10. General Motors Request for Suspension of 1975 Federal Emissions
Standards (Vol I, II, III), March 1973
11. Submission Upon Remand (Vo. I, II), Ford Motor Company,
March 1973
12. Technical Appendix, Administrator's Decision, Envivonmental
Protection Agency, April 1973.
13. General Motors Request for Suspension of 1975 Federal Emissions
Standards (Vol. I, II), April 1972.
14. Rivard, J. G. Closed-Loop Electronic Fuel Injection Control
of the Internal-Combustion Engine, SAE Paper 73000L--, Jan. 1973.
15. Zechnall, R. ; Baumann, G. ; and Eisele, H. Closed-Loop Exhaust
Emission Control System with Electronic Fuel Injection,
SAE Paper 730566, May 1973.
16. Hirschler, D. A.; Adams, W. E. ; Marsee, F. J. Lean Mixtures,
Low Emissions and Energy Conservation, Paper presented at the
National Petroleum Refiners Association Meeting, April 1973.
4-2
-------
17. Lang, R. J. A Well-Mixed Thermal Reactor System for Automotive
Emission Control, SAE Paper 710608, June 1971.
18. Medium Duty Truck Emissions Data, Environmental Protection
Agency, Ann Arbor
19. Fuel Economy and Emission Control, Environmental Protection
Agency, Nov. 1972.
20. Hinton, M. G. ; lura, T; Mcltzer, J. ; Somers, J.H. Gasoline
Lead Additive and Cost Effects of Potential 1975-76 Emissions
Control Systems, SAE Paper 730014, Jan. 1973.
21. Campau, R. M. Low Emission Concept Vehicles, IIEC 1971
Report, SAE SP-361.
22. Springer, K. J. Baseline Characterization and Emissions Control
Technology Assessment of HD Gasoline Engines, Final Report
For Contract EHS 70-110, Nov. 1972.
23. Vehicle Operations Survey (Vol. I, II) Scott Research Laboratories,
Inc., December 1971.
24. International Harvester Co. , Application for Suspension of the
1975 Federal Light Duty Emission Standards, March 1973.
25. Springer, K. J. Emissions from a Gasoline and Diesel Powered
Mercedes 220 Passenger Car, Final Report for Contract No. CPA
70-44, June 1971.
4-3
-------
26. Marshall, W.F. and Fleming, R.D.; Diesel Emissions Re-
inventoried, Bureau of Mines Report RI 7530.
27. Marshall, W.F. and Hurn, R.W. ; Modifying Diesel Engine
Operating Parameters to Reduce Emissions, Bureau of Mines
Report RI 7579.
28. Bureau of Mines, Characterization and Control of Emissions
from Heavy Duty Diesel and Gasoline Fueled Engines, Draft
of Final Report on EPA-IAG-0129 (D), Oct. 1972.
29. Spindt, R.S., Barnes, G.J., Somers, J.H.; The Characterization
of Odor Components in Diesel Exhaust Gas, SAE Paper 710605
June 1971.
30. Dodd, A.E., and Wallin, J. C., The Subjective Assessment of
Exhaust Smoke from Diesel-Engined Road V hides, Motor
Industry Research Association Report No. 1971/10, Nov. 1971.
31. Bascom, R.C., Broering, L. C. , Wulfhorst, D. E. ; Design Factors
that Affect Diesel Emissions, SAE Paper 710484, Also published
in SP-365, July 1971.
32. Walder, C.J.; Reduction of Emissions from Diesel Engines,
SAE Paper 730214, Jan. 1973.
33. Norbye, J.P. and Dunne, J. ; Honda's New CVCC Car Engine
Meets '75 Emission Standards Now, Popular Science, April 1973.
4-4
-------
34. Austin, T.C. , An Evaluation of Three Honda Compound Vortex
Controlled Combustion (CVCC) Powered Vehicles, Dec. 1972.
35. Technical Report on Honda CVCC System, Honda Motor Co. ,
May 1973.
36. Private Communication from M. G. Hinton, Aerospace Corporation
37. Tingley, D. and Johnson, J.H.; The Development of a Computer
Model for the Prediction of the U.S. Truck and Bus Population,
Fuel Usage, and Air Pollution Contribution. 4th Annual Pittsburgh
Conference on Modeling and Simulation, April 1973.
38. Motor Vehicle Manufacturers Association Publications
0
39. Automobile Exhaust Emission Surveillance - A Summary prepared by
Calspan Corporation for the Environmental Protection Agency, Div. of
Certification and Surveillance, Ann Arbor, March 1973.
40. National Academy of Science, Committee on Vehicle Emissions,
Panel #4, Alternative Power Systems.
41. Fett, C. E. , Catalyst Deterioration Factors, EPA Memo, June 1973.
4-5
-------
REFERENCES PART B
1. Ford Motor Company, Submission Upon Demand, Ford's Application for
Suspension of 1975 Motor Vehicle Exhaust Emission Standards, Vol. I,
March 5, 1973.
2. Data developed by L. Lindgren, Rath and Strong Associates.
3. Report by the Committee on Motor Vehicle Emissions of the National
Academy of Sciences, 15 February 1973.
4. An Assessment of the Effects of Lead Additives in Gasoline on Emission
Control Systems which might be used to meet the 1975-1976 Motor Vehicle
Emission Standards, Final Report, Aerospace Corp. , 15 Nov. 1971.
5. Ford Motor Co. , Response to National Academy of Sciences Committee
on Motor Vehicle Emissions, October 13, 1972.
6. Telcom with G. Storbeck, Volkswagen of America, 14 May 1973.
70 Telcom with J. Rivard, Bendix Corporation, 15 May 1973.
8. Telcom with John Mapleback, Ford Motor Co. , 8 March 1973.
9. Effect of Lead Antiknocks on the Performance and Costs of Advanced
Emission Control Systems, E. I. Dupont de Nemours & Co. , Inc. ,
July 1971.
10. Telcom with Charles Bailey, Universal Oil Products, 9 March 1973.
11. Letter to John P. DeKaney from Fred W. Bowditch, 22 Dec. 1972,
Subject: GM Cost Information on Advanced Emission Control Systems
under Development.
12. Information provided by R. Kruse, EPA, Ann Arbor, Michigan.
13. Final Report, Assessment of Domestic Automotive Industry Production
Lead Time for 1975/1976 Model Years, Aerospace Corp. , 15 December
1972.
14. Telcom with Mr. Feiton, General Motors Corp. , April 1973.
4-6
-------
APPENDIX A-l
COMPARISON OF SPECIFICATIONS
FOR ENGINES USED IN LDV AND
HDV APPLICATIONS
A-l
-------
The same basic engine families are generally used by the automo-
bile manufacturers in their passenger cars and light duty vehicles (under
6, 000 Ibs GVW) and in their medium duty trucks (6, 000-14, 000 Ibs GVW).
Engine families are designated by the manufacturers as comprised of those
engines that share a common engine block casting; identical cylinder arrange-
ment, bore spacing and deck height. Engines classified within a given family
may have different displacements resulting from changes in bore and/or stroke
dimensions. Similarly, horsepower ratings of engines with a given displace-
ment may be found to differ because of changes in carburetion, compression
ratio, camshaft lift and/or duration, etc.
Tables A-l. 1 through A-1.4 provide a comparison of the engines
used by Chrysler, Ford, General Motors and International Harvester in their
light duty and medium duty vehicles. These data were culled from information
submitted by each manufacturer to EPA in their LD and HD Gasoline Engine
Certification Books on 1973 models. Within any one family, all of the light
duty engines are included whereas, in the heavy duty families, only those
engines used in vehicles with GVW ratings between 6,000 and 14,000 Ibs are
listed. A listing of the emission control devices used on each is given as well.
Generally, the heavy duty engines are equipped with fewer external
emission control devices and are rated at a slightly higher power output.
Close scrutiny of the detailed specification sheets in the source documents
showed that, with few exceptions, the LD and HD engines were identical in-
ternally (same camshafts, heads and compression ratios). Such internal
differences as were noted were relatively minor. One example would be a
difference in exhaust valve material.
Emission controls used on the heavy duty engines are seen to be
taken directly from their light duty counterparts. Engine modifications and
A-3
-------
positive crankcase ventilation systems are used by all engines listed. Those
heavy duty engines sold in California are equipped with EGR and evaporative
control systems to comply with the 1973 standards for that state.
Emission control devices are identified only by their acronyms in
Tables A-l. 1 through A - 1. 4. Table A-1.5 identifies these acronyms according
to their meaning and provides a brief description of the purpose and functioning
of the control devices.
A-4
-------
TABLE A-l. 1
ENGINE -COMPARATIVE DATA
1973 Chrysler Corp. Light Duty Engines vs Chrysler Corp. Heavy Duty Engines
Engine Family
RG
(I
tt
U
it
ti
U
U
B
11
II
RB
it
it
ii
U
ii
Engine Type
I 6
ii
ii
V 8
II
tl
It
tl
V 8
It
It
V 3
11
U
ii
U
U
Displacement
198
225
n
318
It
3UO
360
It
UOO
II
fl
1.13
UUO
n
n
n
n
Carhuretion
1 - 1 BBL
1 - 1 BBL
II
1 - 2 BBL
(1
1 - h BBL
1 - 2 3KL
ii
1 - 2 BBL
n
1 - U BBL
1 - h EBL
1 - k BBL
n
it
it
ii
light Duty
HP £ tPM
95 @ UOOO
98 @ UOOO
105 @ Uooo
150 e 3600
170 @ Uooo
2UO © tiSOO
163 e Uooo
170 e Uooo
175 @ 36oo
185 c«- 3600
260 Si U800
208 t 3600
213 ® 3600
215 £' 3600
220 £ 3600
280 ft U800
Control Devices
PCV,OSAC,EGR,CAN
PCV,OSAC,EGR,
CAN,AI .
n
?CV,eSAC,TinC,
E3R,CAN
it
PCV,OSAC,TIDC,
EGR,CAN
°CV,OSAC,TIDC,
5GR,CAN,AI
ti
PCV,03AC,TIDC,
EGR,CAN
n
PCV,OSAC,TIBC,
SOP., CAN
PCV,OSAC,TIDC,
EOR,CAN,AI
ti
it
n
?CV,OSAC,THX;,
ST,R,CAN
Heavy Duty
HP ® RPM
110 <£ UOOO
150 £ UOOO
160 e Uooo
160
-------
TABLE A-1.2
ENGINE COMPARATIVE DATA
1973 Ford Light Duty Engines vs Ford Heavy Duty Engines
Engine Family
2UO-300
ti
it
H
it
n
302
330-361-391
360-390
II
*|
tt
Engine Type
I 6
"
ti
it
n
1!
V 8
V 8
V 8
it
n
n
Displacement
2liO
it
300
n
ii
it
302
330
360
M
390
n
Carburetion
1 - 1 BBL
ii
1 - 1 BBL
n
it
M
1 - 2 BBL
1 - 2 BBL
1 - 2 BBL
11
1 - 2 BBL
n
Light Duty
HP @ R?M
95 ® 3800
99 © 3800
1UO e UOOO
152 © UOOO
153 @ UOOO
162 £' UOOO
Control Devices
PCV,TCS,EGR,CC
ti
PCV,SDV,EGR,CC
PCV,SDV,EGR,CC
n
PCV,SDV,EGR,CC
Heavy Duty
HP g RPH
11U © 3UOO
117 @ 3600
118 @ 3UOO
126 @ 3UOO
139 @ 3600
137 ® 3200
1U8 @ 3800
153 ® 3UOO
161 @ 3600
Control Devices
. IMCO,PCV,CC
it
n
it
IMCO,?CV,CC
IKCO,PCV,CC
IMCO,?CV,EGR,CC
IKCO,?CV,EGR,CC
it
Note
C
C
C
A,C
C
A,C
B,C
B,C
II
NOTES: A - The 126 HP, 300 cu in six and the 330 cu in V-8 are available only in the F-500 and heavier trucks.
The GVW ratings of the F-500 start at 1UOOO#.
B - The heavy duty versions of the 360 and 390 cu in V-8's have exhaust gas recirculation systems in
California only.
C - Heavy duty versions of these engines have carbon canister (CC) evaporative controls in California
only, on fuel systems with a total'capacity of 50 gallons or less.
-------
TABLE A-l. 3 ENGINE COMPARATIVE DATA
1973 Chevrolet (CMC) Light Duty Engines vs Chevrolet (OMC) Heavy Duty Engines
Sngine Family
io2*i in**
112**
10U*i- 113**
:t
If
M
II
II
II
II
II
105** 115**
II
II
II
Sngine Type
I 6
I 6
V 8
n
»
n
n
ii
n
u
ii
V 8
11
»
it
Displacement
250
292
30?
350
II
II
It
II
tt
It
100
li$k
n
n
n
Carburetion
1 - 1 3BL
1 - 1 BBL
1 - 2 BEL
1 - 2 BBL
n
1 - I BBL
If
II
It
II
1 - 2 BEL
I - I EBL'
n
n
it
Light Duty
HP @ RPK
100 e 3600
115 e 3600
H5 e Ijcoe
155 £ hOOO
175 e 14000
190 e Moo
2u5 e 5200
250 E 5200
150 6 3200
215 e Uooo
2Lo e Uooo
2L5
-------
TABLE A-1.4 ENGINE COMPARATIVE DATA
1973 International Harvester Light Duty Engines vs International Harvester Heavy Duty Engines
Engine Family
6 - 256
V - 30h
V - 315
V - 392
Engine Tyoe
I 6
V 8
V 8
v e
Displacement
258.1114
303.68
3LA.96
390.89
Carburetion •
1 - 1 3BL
1 - 2 BPL
1 - 2 BBL
1 - h BBL
light Duty
HP @ R?M
iho <£ 3800
193 @ hhOO
197 £ UCOO
253 @ h200
Control Devices
PCV,AI,EGR,SCS,CC
PCV,AI,EGR,SC3,CC
^V.AI^GR.SCSjCC
PCV,AI,EGR,SCS,CC
Heavy Duty
H° @ R°K
193
-------
TABLE A-1.5
- SUMMARY OF EMISSIONS CONTROL DEVICES PRESENTLY USED
Abbreviation
Syst em Name
System Description
PCV
AI
EGR
TCS
SDV
OS AC
TIDC
GMECS
cc
CAN
EM
CCS
IMCO
Positive Crankcase Ventilation
System
Air Injection System
Exhaust Gas Recirculation System
Transmission Controlled Spark
Spark Delay Valve
Orifice Spark Advance Control
Thermostatic Ignition Distributor
vacuum Control
General Motors Evaporative Control"^
System \
Carbon Canister
CANister evaporative control
\
j
Engine Modifications
Controlled Combustion System
IMproved CObustion System
\
)
A system which supplies fresh air to the crankcase through
the air filter and directs the blow-by gases into the intake
manifold through a spring-loaded metering valve.
A system consisting of an engine-driven air pump
which supplies fresh air to nozzles located in the
exhaust ports, completing combustion of hydrocarbons
externally. The systems usually incorporate some flow
control devices for better driveability.
A system which controls oxides of nitrogen (NOX )
emissions by recirculating a portion of the exhaust gases
back into the intake manifold. The plumbing consists
of fixed orifices or vacuum-controlled valves.
All of these systems are ignition modifications to
control spark advance under various speed or
load conditions.
All of these systems are evaporative emissions control
systems consisting basically of a charcoal or carbon
filled canister into which the evaporated hydro carbons
from the gas tank and carburetor are directed. They
are held here until the engine is started at which time they
are purged into the intake manifold
These systems, used on heavy duty engines, consist
mainly of modifications and recalibrations made on basically
unchanged pre-emission controls engines. The carburetor
and choke are modified, the spark advance curve is altered,
the compression ratio is lowered, the head design is
altered, a system to pre-heat intake air is installed, the
camshaft profile is altered, etc.
-------
APPENDIX A-2
A SUMMARY OF EXHAUST
EMISSIONS DATA FROM MEDIUM DUTY
VEHICLES 6,000 - 14,000 POUNDS GVW
A-ll
-------
This appendix simply presents a tabular summary of the exhaust
emissions data for motor vehicles in the nominal 6, 000 - 14, 000 pound GVW
range. These data were measured by EPA and its two contractors, Southwest
Research Institute (SWRI) and Automotive Engineering Systems, Inc. (AESI),
using an equivalent 1975 Federal Test Procedure. The only deviations from
the 1975 FTP occurred in the determination of vehicle inertia weight and
vehicle road load horsepower.
Inertia weight was obtained by adding an incremental weight to the
curb weight of the vehicle and rounding this sum to the nearest 500 Ibs. The
incremental weight to be added was established by reference to the following
table.
Incremental Weight (Ibs)
500
1000
1500
Vehicle Payload Capacity (GVW-GCW)
2000 Ibs
2000-4000 Ibs
4000 Ibs
With the inertia weight established, the corresponding road load
horsepower to be used for that vehicle was calculable from the following
relation.
Road load HP = 0. 0096 (inertia weight Ibs) - 30. 3
The attached sheets itemize the data by the test organizations
vehicle number; vehicle model year; vehicle make, model, year and body type;
GVW, GCW and inertia weight, engine displacement and number of cylinders;
averaged emissions for HC, CO, CCK and NOX in grams per mile; number of
A-13
-------
tests averaged and whether the engine had been tuned prior to the test.
Data for 122 vehicles are listed and of this total 12 are motor
homes. The preponderant body type vehicle sampled was the pickup/camper.
Approximately 75% of these vehicles were 1970 and later models. Excluding
motor homes, approximately 55% of all vehicles were tested at an inertia
weight of 5000 and 5500 pounds and only 6% in the range above 8000 pounds.
Vehicles numbered 1 through 67 were tested by EPA as a part of
an in-house study. Vehicles numbered 200 through 245 were tested by SWRI
while those coded 1A through 45A (the letter A was arbitrarily added to
differentiate from the EPA group of vehicles) were tested by AESI.
Generally all 1972 and 1973 model vehicles were tested after the
engine had been "tuned". In the earlier stages of the test programs, the
tuning only involved setting the idle rpm to specifications. Later, the tuning
procedure was extended to include adjustment of the initial timing and the
dwell angle.
A-14
-------
EPA
Vehicle
No.
1
2
3
4
5
6
7
8
9
10
11
i 12
£ 13
P 14
15
16
17
18
19
20
21
22
23
24
25
26
27
Year
72
66
71
68
71
72
72
72
72
70
72
72
71
69
71
70
67
72
72
71
69
71
65
69
71
71
68
Make
Chev.
Dodge
AMC
Dodge
I-H
Ford
Chev
Ford
Dodge
Dodge
Chev
Ford
Dodge
Ford
Chev
Ford
Ford
Chev
Ford
Chev
CMC
Chev
Chev
Ford
Ford
Ford
Ford
Model
C-20
D-100
J4000
B300
-
F-350
P-35
E-300
D-300
-
C-35
F-250
D-300
E-300
C-30
E-300
F-350
C-20
F-250
C-30
Sierra
Grande
C-20
C-20
F-250
E-300
E-300
F-250
Body
Type
Pickup
Pickup
Pickup
Van
Multi-
Stop
Van
Van
Van
Pickup
Motor
Home
Stake
Pickup
N/A
Van
N/A
Van
N/A
Pickup
Pickup
Van
Pickup
Pickup
Pickup
Motor
Home
Van
Van
Pickup
GVW
7,500
5,200
7,000
7,700
6, 100
10, 000
10,000
6,050
9,000
10,000
10,000
6,900
10,000
6,800
10,000
6,500
10,000
10,000
6,900
10, 000
7,500
6,200
7,500
6, 100
7,600
6,050
7,500
GCW
4,385
3,620
4,265
5,565
4,295
6,620
6,760
4, 110
5, 185
8,645
5,395
4,460
5,575
4, 170
5,580
4,235
6,630
6,770
4,120
6, 820
4,730
4,920
4,325
6,315
5,840
4,340
4,620
Inertia
Wgt.
5,000
4,000
4,265
6,500
5,000
7,500
7,500
4,500
6,000
9,000
7,500
5,000
6,000
4,500
6,000
4,500
7,000
7,500
4,500
7,500
5,000
5,500
5,000
7,000
6,500
5,000
5,000
Engine
350-8
225-6
360-8
318-8
232-6
300-6
350-8
240-6
400-8
318-8
350-8
360-8
318-8
240-6
350-8
240-6
300-6
350-8
300-6
350-8
396-8
350-8
250-6
360-8
302-8
302-8
240-6
Av.
HC
3. 14
3.05
6.05
5.52
4.02
2.89
3.86
2.76
3.58
9.32
2.43
4.43
4.83
6.87
6.13
4.55
6.48
5.32
2.50
5.19
6.95
5.97
7.69
8.06
9.35
6.94
8.49
Emissions, gm/mile
CO
19.32
49.92
24.44
56.02
65.18
43.67
65.46
28.78
57.44
158.98
29.82
26.46
58.52
14.65
79.32
39.32
65.75
47.26
29.57
61.39
83.64
37.05
70.49
116.06
59.00
73.95
94.47
C02
875.88
591.11
945.76
697.69
698.50
955.35
1144.03
682.94
851.52
1082.03
1240.35
842.47
952.37
560.53
767.81
627.09
872.67
976.68
631.80
1058.20
734.11
757.78
532.08
934.45
786.11
695.26
569. 85
NOX
4.88
5.70
7.66
9.43
5.63
10.77
9.32
5.40
5.91
14.85
9.02
12.63
9.99
5.38
9.45
6.67
15.97
12.04
10.95
12.44
7.03
8.56
8.99
15.82
15.55
6.58
6.53
No. of
Tests
2
2
2
2
2
2
2
2
2
4
2
4
4
2
4
4
2
4
4
4
Z
2
2
3
2
2
2
Eng.
Tuned
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
-------
Vehicle
No.
28
29
30
31
32
33
34
35
36
37
38
39
40
> 41
-42
*• ,,
cr 43
44
45
46
47
48
49
50
51
52
53
54
55
56*
57*
Year
70
70
66
68
72
66
71
71
69
72
65
71
71
71
71
72
72
72
72
70
69
70
72
71
69
73
73
Make
Chev
Ford
Chev
CMC
Dodge
Chev
Ford
Chev
Ford
Ford
Chev
Ford
Chev
Chev
Chev
Ford
Chev
Chev
Chev
Ford
Chev
Ford
CMC
Chev
CMC
Dodge
Ford
Chev
Chev
Chev
Model
C-20
F-250
C-20
C-25
B-300
C-20
N/A
C-30
F-250
F-250
C-20
F-250
C-20
C-20
C-20
F-250
C-30
C-30
C-20
F-700
C-20
F-250
C-35
C-20
C-35
D-300
F-350
C-20
C-20
Body
Type
Pickup
Camper
Pickup
N/A
Van
Pickup
Camper
Camper
Pickup
Pickup
Pickup
Pickup
Pickup
Camper
Pickup
Pickup
N/A
Pickup
Pickup
N/A
Pickup
N/A
N/A
Van
Pickup
Camper
Special
Pickup
GVW
7,500
6,900
7,500
7,500
7,000
7,500
6,900
9,000
6,900
8, 100
7,500
7,500
6,400
6,700
6,400
7,800
23,500
6,200
7,500
14,000
7,500
14,000
10, 000
10,000
7,500
9,000
8,200
GCW
4,900
7,150
4,405
5, 125
4, 160
4,500
4,920
4,198
4,600
4,675
4,650
5,100
4,880
4,600
4,275
. 4,715
8,950
4,540
4,495
8, 180
4,540
8,175
5,200
7,320
4,540
5,170
5,545
Inertia
Wgt.
5,500
5,500
5,000
5,500
4,500
5,000
5,500
4,500
5, 000
5,000
5,000
5,500
5,000
5,000
4,500
5,000
10,000
5,000
5,500
10,000
5,500
10,000
6,500
8,500
5,000
6,500
7, 000
Engine
350-8
360-8
283-8
327-8
360-8
250-6
360-8-
400-8
360-8
360-8
283-8
360-8
307-8
350-8
307-8
390-8
361-8
350-8
250-6
350-8
350-8
350-8
318-8
300-6
307-8
350-8
454-8
Av.
HC
4.97
5.65
13.00
7.65
3.91
9.86
8.17
4.10
12.45
6.35
-
8.06
6.41
4.06
4.21
3.38
6.01
3.20
5.23
6.85
9.70
7.53
4.61
6.64
6.20
1.63
1.68
, Emissions, gm/mile
CO
36.06
78.05
114.47
99.21
31.01
65.94
111.56
43.82
106.61
75.28
-
98.39
48.78
78.23
41.72
38.76
75.80
24.19
32.49
86.66
152.15
83.61
24.41
119.87
31.39
28. 96
11.07
C02
801.89
790.79
609.73
735.49
734.86
669.98
670.72
910.68
710.96
728.02
-
760.73
737.17
713.24
690.36
794.52
1185.69
684.49
737.25
966.76
639.87
986.91
806.88
759.81
641. 15
1000. 18
998.32
NOX
12.77
10.19
6.33
10.75
7.60
13.19
7.01
11.01
6.94
7.97
-
5.67
10.06
6.12
7.80
10.14
16.38
7.03
2.78
13.02
5.48
13.01
8.80
9.01
7.22
5.87
10.53
No. of
Tests
2
2
2
2
2
2
2
3
2
4
1
2
2
2
4
4
2
2
2**
2
2
2
2
2
2
2
2
Eng.
Tuned
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
Yes
Yes
No
No
No
Yes
No
No
Yes
Yes
!:Green Engine
-------
Vehicle
No.
58
59
60
61*
62*
t 63*
64
65
66*
Year
69
73
73
73
73
73
73
73
73
Make
Chev
Ford
Chev
Chev
Chev
Chev
IHC
Chev
Chev
Model
C-20
F-250
C-20
C-20
C-20
C-20
1510
P-30
P-30
Body
Type
Dump-
Bed
Pickup
Pickup
Pickup
Pickup
Pickup
Chassis
St. Van
Earth
GVW
10,000
6,200
6,400
6,800
6,400
6,400
14,000
8,200
11,000
Inertia
GCW Wgt.
7,500
5,000
5,500
5,500
5,000
5,000
8, 000
7,000
8,500
Av. Emissions, gm/mile
Engine
350-8
360-8
454-8
350-8
250-6
292-6
345-8
350-8
454-8
HC
8.18
3.51
1.58
2.03
3.30
3.21
1.28
6.79
2.52
3.61
CO
94.33
50.60
31.18
12.47
33.47
57.59
31.70
67.43
40.51
51.91
C02
759.31
760.87
1091.85
829.63
710.89
1041.36
740.60
931.81
968.25
1202.20
NOX
8.54
4.67
4.69
6.62
3.68
2.50
2.32
4.59
7.18
9.85
No. of
Tests
1
2
2
2
2
2
2
2
2
2
Eng.
Tuned
No
Yes
Yes
Yes
Yes
No
Yes
Yes
Yes
Yes
Mtr.Home
67
73
Ford
F-250
Pickup
6,200
5, 000
360-8
3.91
31.43
763.70
5.73
2
Yes
Start of more extensive tune-up checks *Green Engine
-------
SWRI
Vehicle
No. Year
200
201
202
203
204
205
206
207
208
209
>
^ 210
£ 211
212
213
214
215
216
217
218
219
220
221
222
223
70
69
66
68
71
73
71
66
72
73
70
70
70
72
72
70
69
73
72
73
70
72
72
72
Make
Ford
Chev
Chev
Chev
Chev
Dodge
I-H
I-H
I-H
Ford
Chev
Chev
Dodge
Ford
Ford
CMC
Dodge
Chev
Chev
Chev
Ford
Ford
Dodge
CMC
Model
F-250
C-20
C-20
C-20
C-20
N/A
1210
Metro
Van-1200
1210
E-300
C-30
C-20
D-200
E-300
E-300
C-25
D-27
C-20
C-20
C-30
F-350
E-300
C-300
C-35
Body
Type
Pickup
Pickup
Pickup
Pickup
Pickup
Motor
Home
Pickup
Panel
Pickup
Van
Pickup
-P ic kup
Pickup
Van
Van
Pickup
Motor
Home
Pickup
Pickup
Van
Stake
Motor
Home
Stake
Wrecker
GVW
7,500
7,500
7,500
7,500
7,500
11,000
6, 100
8, 000
7,500
7,000
8,000
6,200
7,500
7,000
7,000
6,200
12,000
6,400
6,200
6,400
10,000
8,300
10, 000
9,000
GCW
4,020
4,430
4,260
4,390
4,400
7,730
4,450
5,900
4,710
4,260
4,990
5,990
4,300
4,450
4,080
4,360
9,820
4,900
4,340
4, 040
6,000
6,580
5,350
5,590
Inertia
Wgt.
5,000
5,500
5,500
5,500
5,000
8,000
5,000
7,000
5,500
5,500
6,000
6,500
5,500
5,500
5,000
5, 000
11,000
5,500
5,000
5,000
7,500
7,500
7,500
7,500
Engine
240-6
292-6
327-8
327-8
350-8
318-8
345-8
266-6
304-8
302-8
292-6
250-6
318-8
302-8
302-8
292-6
318-8
454-8
350-8
350-8
300-6
302-8
318-8
350-8
AV.
HC
9.69
6.18
39.07
19.70
3.48
. 8.97
6.02
18.50
4.72
4.35
5.82
5.30
7.11
6.35
5.59
4.24
5.84
5.86
6.02
5.13
5.34
7.01
5.23
4.01
5.55
8.24
8.00
9.95
Emissions, gm/mile
CO
139.06
68.39
122.61
236.05
24.20
126.39
64.91
170.41
41.37
59.76
38.40
31.87
76.53
91.58
37.40
68.51
40.75
53.20
88.72
70.52
40.52
49.46
45. 10
72.78
72.23
77.66
79.97
82. 11
CC-2
502.33
508. 11
648.45
532.02
717.08
1008.05
617.20
702.84
677.79
734.00
629.83
706.37
655.10
659.79
604.05
774.11
628.82
593.33
757.98
860.91
634.38
636.89
820.52
855.51
818. 19
846.14
793.44
523.44
NOX
5.93
4.81
4.88
2.75
6.82
12.88
4.13
5.56
8.47
5.14
4.73
3.80
7.21
8.40
5.29
4.13
3.53
7.37
6.34
4.26
4.97
4.82
4.04
11.45
7.26
6.77
5.13
7.03
No. of
Tests
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
. 2
2
2
2 '
Eng.
Tuned
No
No
No
No
No
Yes
No
No
No
Yes
No
Yes
No
No
No
Yes
Yes
No
No
Yes
No
Yes
Yes
No
Yes
No
Yes
Yes
-------
Vehicle
No.
224
225
226
227
228
229
230
231
232
233
234
> 235
i236
>£k
» 237
238
239
240
241
242
243
244
245
Year
70
67
67
72
72
67
67
65
71
68
68
72
66
69
73
71
73
72
72
72
Make
Ford
Ford
Ford
I-H
Chev
I-H
Chev
Ford
Ford
Chev
Ford
CMC
Ford
Ford
Ford
Chev
I-H
Ford
Winne-
Bago
Champ-
Model
F-250
F-250
F-250
1210
C-20
1200
C-20
F-350
F-350
C-20
F-250
P-35
F-250
F-250
E-300
C-20
1310
F250
D22
(Dodge)
Body
Type
Pickup
Pickup
Pickup
Travel-
All
Pickup
Crewcab
Pickup
Pickup
Platform
Platform
Pickup
Pickup
Van
P ic kup
Pickup
Econo.
Panel P. U
Pickup
Pickup
Pickup
Motor
Home
Motor
GVW
6, 100
6, 100
6, 100
7,500
6,200
7,300
7,500
10,000
10,000
7,500
7,500
7,500
7,500
6, 100
8,300
•
6,200
10,000
6,900
13, 000
11, 000
GCW
5,000
5,100
5,100
5,380
4,800
4,820
6,000
7, 120
7,210
4,190
4,490
6,960
5,100
4,500
4,340
4,500
Inertia
Wgt.
5,500
6,000
6,000
6,500
5,500
6,000
6,500
8,200
8,200
5,000
5,500
7,500
6,000
5,000
5,500
5,000
7,500
6,000
8,500
8,500
Engine
360-8
240-6
240-6
345-8
350-8
241-6
250-6
240-6
360-8
307-8
240-6
292-6
240-6
360-8
302-8
350-8
304-8
300-6
413-8
318-8
Av.
HC
9.90
10.23
13.42
5.22
'3.19
13.68
12.16
20.95
12.85
11.00
7.56
5.35
10.97
8.04
6.21
5.63
10.88
6.30
13.96
8.23
Emissions, gm/mile
CO
126.58
146.27
145.05
67.33
56.82
128.98
118.45
182.82
116.28
135.10
78.97
79.61
140.10
103.50
47.22
50.27
131.80
112.03
139.45
141.49
CC-2
855.21
707.96
719.13
613.69
527.89
844.30
611.02
630.76
749.96
482.41
477.71
788.42
519.29
582.09
566.46
656.20
859.84
737.09
1131. 14
996.29
NOX
4.00
2.66
2.30
5.98
7.46
3.50
6.00
5.27
6.93
1.22
5.67
7.22
1.78
2.81
5.69
5.01
3.16
8. 12
14.92
11.96
No. of
Tests
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
• 2
2
2
Eng.
Tuned
No
No
No
Yes
Yes
No
No
No
No
No
No
Yes
No
No
Yes
No-
Yes
Yes
Yes
Yes
Note: Blank spaces or those marked "N'/A" signify that no information was furnished.
-------
AESI
Vehicle
No.
1A
3A
5A
7A
10A
11A
13A
|27A
t
35A
39A
40A
43A
44A
45A
Year
72
73
73
72
72
72
72
72
73
73
73
72
72
72
Make
Ford
Chev
Ford
Ford
Ford
Chev
Chev
Dodge
Ford
Dodge
Dodge
I-H
Ford
I-H
Model
F-250
G30
Econol.
F-250
Econol.
C-20
C-20
F-250
Surveyor
Surveyor
1510
Condor
Winne-
Bago
Body
Type GVW
Pickup
Van
Van
Pickup
Van
Pickup
Pickup
Motor 11,000
Home
Motor 11,000
Home
Box 14,000
Van
Motor 15,000
Home
Motor
Home 13,000
Inertia
GCW Wgt.
4,500
4,500
4,500
5,000
4, 500
5,500
5, 000
5,000
5,000
8,500
8,500
6,000
8,500
8,500
Engine
300-6
350-8
302-8
360-8
302-8
350-8
350-8
360-8
360-8
413-8
413-8
345-8
390-8
304-8
Av.
HC
3.77
2.98
4.57
2.27
4.31
3.05
'6.23
5.13
6.09
5.83
4.05
3.47
5.36
5.41
5.85
3.95
3.91
4.47
6.97
6.42
10.49
7.30
7.46
5.58
7.45
5.34
12.61
5.29
Emissions, gm/mile
CO
47. 84
32.33
47.26
23.26
85.31
31.46
55.40
44.18
91.68
84.73
40.34
29.90
62.37
34.08
118.16
68.37
53.89
97. 15
123.13
109.46
196.56
231.95
54.06
51.69
89.54
82.86
47.50
68.66
C02
567.36
562. 13
651.80
728.21
648.00
711.00
745.00
728. 00
635.00
665.00
855.00
829.00
642.00
674.00
734.00
745.00
778.89
804.94
1079. 16
1145.59
1251.17
1113.84
771.92
874.88
1082.22
1253.81
1124.63
1188.56
NOX
8.48
6.75
4.00
4.52
4.55
3.90
7.36
6.35
3.50
3.39
9.91
10.02
6.85
8.13
7.76
8.60
4.90
4.57
13.06
13.02
16.98
9.63
8.44
7.02
15.74
15.58
17.61
17.51
No. of
Tests
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
•2
2
2
2
2
2
2
Eng.
Tuned
No
Yes
No
Yes
No
Yes
No
Yes
No
Yes
No
Yes
No
Yes
No
Yes
No
Yes
No
Yes
No
Yes
No
Yes
No
Yes
No
Yes
-------
APPENDIX A-3
EVAPORATIVE EMISSIONS
A-15
-------
- In earbufetted, gasoline-fueled motor vehicles, the venting of fuel
vapors into the atmosphere from the carburetor and the fuel tank constitutes
a significant source of HC emissions in the absence of any control devices.
It has been estimated that evaporative losses account for approximately 20%
of the total HC emissions from an uncontrolled (pre-1968) light duty vehicle.
This factor would obviously increase greatly in the situtation where the exhaust
emissions were systematically decreased while no control was exercised over
the evaporative sources. This is precisely the situation that exists and will
continue to obtain for at least the near future for the medium duty vehicle. At
present there are no contemplated Federal standards for evaporative emissions
for any motor vehicles other than the light duty group. Only the state of
California has imposed evaporative emissions standards for heavy duty vehicles
commencing with the 1973 models. While the evaporative emissions have not
been controlled for medium duty trucks (except in California, as noted), this
class of vehicle has benefitted, insofar as exhaust emission controls are con-
cerned, from the progress made in the light duty class of vehicle via the shar-
ing of many common engines.
The progress in exhaust emission control for MDV can be quantified.
Mean hydrocarbon emission from a sample of 585 pre-control light duty
vehicles (1957-1967 model years) were found to be 8. 94 grams /mile (1975
(2)
FTP) . On the other hand, the mean level of HC emissions for an MDV at
an inertia weight of 4500 Ibs, corresponding to a full-size passenger car, is
given as 4. 7 grams/mile in Figure 2. 7 (Section 2. 4. 3) of this report. Thus
even comparing LDV with MDV, a significant reduction of exhaust emission of
HC has been identified. As a consequence, the need for evaporative controls
for the medium duty class of vehicle is evident.
A-17
-------
Evaporative controls can virtually eliminate HC vapors emitted
from the carburetor and fuel tank. Probably the most effective .method of
control is through the use of cannisters of activated charcoal to trap and store
the fuel vapors. Activated charcoal has strong affinity for HC and can store
(3)
(on a recycle basis) 30-35 grams per 100 grams charcoal without breakthrough.
Typically, a vehicle system will use 700-800 grams of activated charcoal.
The evaporative control system is so designed that during vehicle
operation, the tank and carburetor vapors are inducted into the engine and
burned. During nonoperative periods, the vapors are stored in the charcoal-
filled cannisters. When the engine is restarted, filtered air is used to purge
the cannisters of vapors which are metered into the vehicle intake manifold and
subsequently burned in the engine.
The problem in evaporative control is simply one of routing all
of the vapors into a trap or cannister. Trapping of fuel tank vapors is relatively
straightforward since all vents and aperatures are readily identified and con-
trolled. The tank filler pipe is sealed by using a low pressure filler cap
( ~2 psi). A relief valve allows air to enter the tank as the fuel is consumed.
Vapors emanating from the carburetor are much more difficult to
(4)
contain because of the many leak sources associated with this component.
Fortunately, this problem is not serious during vehicle operation since the
interior of the carburetor is usually at a slightly reduced pressure (relative
to atmospheric) so that the vapors are inducted into the engine and burned.
Tests reported in Reference 4 show that for one particular vehicle, carburetor
losses represented 83% of the total evaporative losses (vehicle not operating).
* crankcase storage of vapors is feasible but less effective
A-18
-------
Tests to measure evaporative emissions follow a procedure (SAE
Procedure J171) that is known as the SHED (Sealed Housing for Evaporative
* — — —
Determinations) technique. Briefly, two types of vapor losses are measured
while the vehicle is enclosed in the SHED, those associated with the diurnal
soak and with the hot soak. The former involves losses that occur over a one-
hour period while the fuel in the tank is raised in temperature in accord with
a specified schedule. The latter involves losses, again over a one-hour
period, while the vehicle cools following completion of a complete 1975 FTP
(CVS-CH) test.
Using SHED techniques, the evaporative losses for 125 non-con-
trolled vehicles tested in Los Angeles were found to average 37. 4 grams per
test. All LDV models, subsequent to the 1971 model, are required to meet
*
a standard of 2 grams HC per test (by a different test technique) .
There does not appear to be any reason by medium duty vehicles
cannot meet the evaporative emission standards being imposed on light duty
vehicles through the simple expedient of adapting the same control techniques.
No untoward mechanical problems are visualized. Fuel tank designs with a
dead volume (to permit thermal expansion of fuel without forcing the liquid
fuel into the vapor storage device), patterned after LDV tanks, would be required.
Concern with the possibility of creating a flammable mixture
within the engine compartment as the result of the release of vapors from
evaporative controls because of extreme underhood temperatures and high fuel
volatility led to a series of investigative measurements several years ago at
GM. These measurements showed that the HC concentrations were several
* Current EPA certification procedures specify a vapor-trap technique (Federal
Register, Vol. 37, No. 221, Nov. 15, 1972) which results in lower numerical
values of evaporative emissions than the SHED method because of an inability
to trap all the vapors from all sources.
A-19
-------
times lower than the lean flammability limit. In general the engine compartment
concentrations were comparable for the same vehicle whether tested with or
without evaporative controls. These data are circa 1969. Such tests would
probably need to be repeated in MDV in case thermal reactors would be used
for exhaust emission control. The underhood temperatures would be much
higher in such a situtation. If a potentially dangerous condition were to be
found, appropriate design changes would need to be made.
In summary, therefore, it appears that evaporative emission con-
trols can be readily adapted to medium duty vehicles. The fact that all heavy
duty trucks (1973 models with fuel tank capacity^ 50 gals. ) being sold in
California are required to have evaporative controls, would substantiate the
validity of the foregoing conclusions.
A-20
-------
REFERENCES
1. "The Automobile and Air Pollution - A Program for Progress, Part II",
U.S. Department of Commerce, December 1967.
2. McAdams, H. T. , et al, "Automobile Exhaust Emission Surveillance -
A Summary", Calspan Corporation, no number, December 1972.
3. Patterson, D. J. and Henein, N. A. , "Emissions from Combustion Engines
and Their Control", Ann Arbor Science Publishers, Ann Arbor, Michigan,
797T
4. Martens, S. W. and Thurston, K.W. , "Measurement of Total Evaporative
Emissions", SAE Paper 680 125.
5. Martens, S. W. , "Evaporative Emission Measurements with the Shed -
A Second Progress Report", SAE Paper 690502.
A-21
-------
APPENDIX A-4
IDENTIFICATION AND DESCRIPTION OF
EMISSION CONTROL SYSTEM COMPONENTS
A-23
-------
The emissions control systems evaluated in Section 2. 6 for
medium duty truck applications are listed in Table 2.10. The various
components in the control systems are identified and described briefly
in this Appendix.
El - Electronic Ignition
A breakerless ignition system consisting of a rotor, magnetic
pick up coil, and electronic switch assembly. It appears all manufacturers
will use electronic ignition systems to improve the durability of emission
control systems.
FC - Fast Choke
An electric assist fast choke to reduce the time period in which
the engine is running fuel rich during engine warm-up. There will be a
continuing series of carburetor/choke modifications to reduce emissions
when the engine is cold. FC is intended to represent the first generation
of such modifications which will or have appeared on 1973-74 cars.
QHI - Quick Heat Intake
Quick heat intake manifold using hot exhaust gases to vaporize
the fuel to minimize choke time during engine warm-up. Rapid warm-up
is accomplished by maximizing the available heat energy and minimizing
the thermal inertia of the hot spot in the intake manifold.
A-25
-------
AI - Exhaust Manifold Air Injection
Air injection into the cylinder exhaust ports of the engine. This
includes an air pump, distribution manifold, and exhaust port liners, but
does not include a lined, insulated exhaust manifold.
EGR - Exhaust Gas R ecirculation
A portion (5-10%) of the hot exhaust gas is mixed with intake air
in the carburetor downstream of the throttle plate. This includes provision
for an opening into the carburetor from the exhaust crossover passage and
an EGR valve. Complex controlled EGR systems are evolving to tailor the
EGR flow to engine operating conditions to improve its effectiveness and to
reduce its determental effect on fuel economy and driveability. EGR is
part of most of the control systems. It is assumed that as the overall
emissions control system becomes more developed and efficient, so will
the associated EGR component in it.
1C - Improved Carburetion
Various carburetor improvements are being developed for use
with the 1975-76 catalyst systems. It has been found that both to protect
the catalyst from over heating and to insure rapid warm-up and good
conversion efficiency it is necessary to control the A/F ratio more closely
than possible with standard (1971-73) carburetors. This has led to the
following carburetor improvements: (1) altitude and temperature
compensation and (2) more flexibility in the control of A/F mixture for
various engine operating modes. Component 1C means the inclusion of
these carburetor developments in the control system.
A-26
-------
CAI - Air Injection Ahead of Catalyst
Air injection ahead of the oxidizing catalyst to provide a lean
mixture into the catalyst. This includes an air pump which is driven at an
RPM proportional to that of the engine.
OC - Oxidizing Catalyst
This catalyst (noble or base metal) converts CO and HC to
CO and HO. It can be either a pellet or monolith type. Estimated
L^ £*
catalyst volumes for various engine CID are given in Table 2. 11. These
volumes are larger than presently being tested in passenger cars but it
is felt this increased volume is needed for truck applications. Since at
present required catalyst volume is determined purely by cut-and-try,
it is difficult to estimate volumes required for various trucks/loads .
RC - Reducing Catalyst
The reducing catalyst converts NO to CO and H?O and must
x
operate in a slightly rich environment. Technology for reducing catalysts
is not nearly as well developed as for oxidizing catalysts. If the A/F
ratio is too rich, then a significant fraction of the NO is converted to
X.
ammonia (NH ) which is subsequently oxidized back to NO in the ozidizing
•j X
catalyst. Hence, the A/F ratio must be controlled within a rather narrow
range to maintain good NO conversion efficiency in the reducing catalyst.
X
There is very limited information available on which to base a selection of
reducing catalyst volume as a function of engine CID. Early work would
seem to indicate it should be slightly larger than the oxidizing catalyst.
The reducing catalyst is placed nearer the engine than the oxidizing
catalyst and often is in a separate container, but not necessarily.
A-27
-------
- Controlled Air Injection
When using a dual catalyst system (Figure A-4. 1) such as
system 4, it is necessary to inject controlled amounts of air both into the
exhaust ports and ahead of the oxidizing catalyst. AI/CAI includes the
AI and CAI components as well as a means of controlling the fraction of
the air to be injected at each location.
EFIC - Electronic Fuel Injection and Control
This system includes injection of fuel into each cylinder intake
port with a complex electronic control system (Fig, A-4. 2), which senses
engine RPM, inlet air temperature and pressure, and exhaust oxygen
concentration. There is a feed back loop by which the fuel injection is
regulated based on desired exhaust O concentration. This is an advanced
system requiring development of hardware, the control logic and the O
sensor.
RC/OC - Three-way Catalyst
This single catalyst simultaneously converts NO ,CO, and HC
to CO and HO. Engine operation must be maintained very near
stoichiometric (14.5 +_ . 1) to attain good conversion efficiency (80-90%)
for all three pollutants. The NO conversion efficiency is especially
sensitive to A/F ratio. EFIC with feedback and an O sensor is needed
to achieve the A/F ratio control required.
A-28
-------
LTR - Lean Thermal Reactor
This is a manifold thermal reactor used in conjunction with
lean carburetor operation. In that case the engine CO and HC emissions
are reasonably low and can be combusted efficiently in the reactor. Since
the heat release is quite low, it is necessary that the reactor have good
insulation to minimize heat loss. Excellent control of the A/F ratio at all
engine operating modes is required so that the carburetor should be at least
as sophisticated as the 1C system. NO emissions are kept low by lean
?c
engine operation and further reduced by EGR.
RTR - Rich Thermal Reactor
This exhaust manifold reactor is used with rich carburetion.
Relatively high HC and CO engine emissions result in high and rapid heat
release in the reactor. The high operating temperatures (2000 F or higher)
result in high efficiency for the burning of the HC and CO. NO emissions
X
are kept low by operating the engine rich and using EGR to reducing NO
X
further.
FIG - Further Improved Carburetion
Advanced carburetor systems are being developed which
further improve fuel atomization and A/F ratio control over the complete
range of engine operating conditions. The objective is to develop a system
which permits liquid fuel operation approaching that possible with a
gaseous fuel. Examples of advanced carburetor developments are the
sted
r(10)
Dresserator device tested by Ford and IFC (Integrated fuel control)
being developed by GM
A-29
-------
IQHI - Improved Quick Heat Intake
Improved quick heat intake represents a further improvement
of the QHI system. It would be used with the FIG fuel system to further
reduce cold engine emissions.
A-30
-------
IMPROVED CARBURETION AND CHOKE
ALTITUDE AND TEMPERATURE
COMPENSATION
QUICK HEAT MANIFOLD
AIR CONTROL
VALVE
AIR
INJECTION
PUMP
EXHAUST GAS
RECIRCULATION
MODIFIED
SPARK
TIMING
HC-CO OXIDIZING
CONVERTER
NOX REDUCING
CONVERTER
(EACH SIDE)
ELECTRONIC IGNITION
Figure A-4.1 DUAL CATALYST EMISSION CONTROL SYSTEM
A-31
-------
AIR-
FUEL
AIR FLOW
METER
EXHAUST GAS RECIRCULATION
IGNITION
I '
ENGINE
\ / \! / \ / \! /
\/ \/ \' \/
M1- v v
AA
INJECTION
I
<* IGNITION FUEL QUANTITY ON-OFF
1 A K
RPM
AIR QUANTITY
ELECTRONIC
CONTROL UNIT
THROTTLE POSITION
i
I
I
[TRANSMISSION LEVEL] 1
A/F
3 WAY CATALYST
OXYGEN
SENSOR
CATALYST
IGNITION SWITCH
COOLANT TEMP.
EXHAUST
GAS
Figure A-4.2 ELECTRONIC FUEL INJECTION AND CONTROL SYSTEM
-------
APPENDIX A-5
SUPPORTING EMISSIONS DATA FOR THE
EVALUATION OF THE EMISSION REDUCTION FACTORS
A-33
-------
TABLE A-5. 1
SUPPORTING EMISSIONS DATA FOR SYSTEM 2
u>
1975 CVS-CH Emissions
gm /mi
Source
Ref (11 ),
Ref (11 ),
Ref (12),
Ref (12),
Ref (10),
Control
System
1C + QHI
+ EGR
1C + QHI
+ EGR
1C + QHI
+ EGR
1C + QHI
+ EGR
1C + QHI
+ AI + EGR
Test Number of
Weight HC CO NOX Tests
5000 1.32 8.35 2.62 16
5000 1.42 9.67 2.2 11
5000 1.24 12.54 1.89 16
4500 1.03 8.43 1.75 4
4500 .90 11.4 2.3 3
-------
I
oo
TABLE A-5. 2
SUPPORTING EMISSIONS DATA FOR SYSTEM 3
AVERAGE 1975 CVS - CH EMISSIONS
(gm/mi)
Number of
Source HC CO NO Vehicles (c)
x
Ref ( 12 )* . 32 1.90 1.95 10
Ref ( 12 )(b) .32 2.73 2.25
(a) GM light duty vehicles
(b) Ford light duty vehicles
(c) Individual vehicles in pre-certification fleet.
(test weight 4500 - 5500 Ibs. )
-------
I
OJ
-vj
TABLE A-5. 3
SUPPORTING EMISSIONS DATA FOR SYSTEM 4
(Reference 13 )
ADVANCED DUAL CATALYST SYSTEMS - OXIDIZING AND REDUCING CATALYSTS
Car
Vega
Chev.
Chev.
Chev.
Temp.
Olds.
Eng.
Displ.
140
350
350
350
250
455
*
Mileage
on Catalyst
0-100
R-100
0-100
R-25
0-463
R-167
0-35
R-45
0-30
R-30
0-1659
R-612
System Description 1975 CVS-CH Emissions (gm/mi)
A. I. E.G.R. I.C. Q.H.I. HC CO NO
x
x x x x .24 1.2 .4
x x x x .69 3.5 .5
x x x .24 1.7 .2
x x x .44 3.2 .2
x x x x .40 3.5 .7
x x x .36 2.7 .4
0 - Oxidizing Catalyst Mileage
R - Reducing Catalyst Mileage
-------
oo
TABLEA-5.4
SUPPORTING EMISSIONS DATA FOR SYSTEM 5
(Reference 15)
Results of 80 Tests
CVS Emissions Average (gm/mi) Range (gm/mi)
HC .15 .1-.25
CO 2.17 1.1-3.3
NO .21 .1-3.5
(a) Data for 1. 5-2 liter engines
-------
TABLE A-5. 5
SUPPORTING EMISSIONS DATA FOR SYSTEM 6
(Reference 1 6)
HC
Modified Cars Make A
Series 1 Modifications
Range
Typical Values
Modified Cars Make B
Series 1 Modifications
(1)
(2)
With Low HC-CO Settings
**
Series 2 Modifications
With Low HC-CO Settings
With Low NO Settings
0.5-0.8
0.7
0.7
0.3
0.6
1975 CVS-CH
Emissions, gm/mile
CO NOX
5-8
5.5
6.4
3.6
7.0
1.1-1.9
1.5
2.2
2. 3
1.4
(1) 400 CID, 4000-lb test weight
(2) 360 CID, 4500-lb test weight
Series 1 Modifications
3-V high-velocity carburetor
Improved carb. air preheat
Modulated EGR
Exhaust port liners
Exhaust reactor
Ignition vacuum-advance regulation
Series 2 Modifications
Series 1 plus:
Starting sequence device
Quick-heat intake manifold
A-39
-------
TABLE A-5.6
SUPPORTING EMISSIONS DATA FOR SYSTEM 7
(Reference 1 3)
1975 CVS - CH Emissions
Average levels (gm/mi)
Manifold Reactor
Fuel
Economy
EGR HC CO NOX Loss
Dupont
Yes ,09 7.2 .80 25%
II EC Package A
Yes .22 3.9 .62 24%
GM Modified Dupont
No
.15 5.8 .78 28%
GM Emiss. Research No. 1 No
.12 7.5 .77 32%
GM Small Volume
No
.18 4.3 .60 38%
GM Sand Insulated
Yes .18 3.9 .70 24%
GM Ceramic
No
.10 8.4 .86
GM Inboard Reactor
Yes .11 3.3 .80
31%
A-40
-------
TABLE A-5.7
SUPPORTING EMISSIONS DATA FOR SYSTEM 8
1975 CVS - CH Emissions
Average Levels (gm/mi)
Source
Ref. ( 11 )
Ref ( 12 )
Ref ( 12 )
Control
System
FIC «»
1C + IQHI + EGR(b)
1C + IQHI + EGR(b)
HC
.75
.49
.43
CO
4.20
4.27
3.86
N0x
2.00
2.24
1.86
Number of
Tests
7
2
2
(a) Ford data
(b) GM data
-------
APPENDIX A-6
SUPPORTING DATA FOR THE
DETERMINATION OF THE FUEL PENALTY FACTOR
A-43
-------
TABLE A-6. 1
FUEL ECONOMY DATA FOR SYSTEM 3
(a)
Vehicle % Change in Method
Manufacturer Weight (Ibs) Fuel Economy of Test Reference
Ford
Ford
Ford
Ford
GM
Chrysler
4700
5760
4950
4500
4500
4500
-14.8 road(d)
-20 6 road
-1.5 road
' +25 CVS-CH
-6.5 CVS-CH
+7.0 CVS-CH
(e)
A \ / 107/1 \
(ID
(ID
.(ID
(b)
(b)
(b)
(a) 1975 pre-certification fleets, catalytic systems.
(b) Change
in fuel economy
calculated using 1973 certification
results and EPA emissions tests of 1975 prototypes of the same
class of vehicle .
(c) Change in fuel economy (MPG) from 1973; average over a
number of vehicles.
(d) City/suburban driving schedule.
(e) -14. 8%, +25% not included in calculation of the average.
A-45
-------
TABLE A-6. 2
FUEL ECONOMY DATA FOR SYSTEM 6
(4)
Cars Make A:
Non-Modified 1970
Lean Reactor Mod. 1970
Non-Modified 1973
As Received
Without EGR Cut-Off
(3)
Fuel Economy, mpg
City
Route
11. 5
10.6
11. 3
10.7
City +
Expressway
(1) Route' 2)
14.9
13.5
14.3
13.4
Average
13.2
12. 1
12.8
12. 1
Loss
%
8. 3
3.0
8. 3
Cars Make B:
Non-Modified 1971
Lean Reactor Mod. 1971
Low HC-CO Settings
Low NO Settings
Non-Modified 1973
11. 1
11. 1
10.8
10. 3
16.7
14.7
14.4
14.1
13.9
12.9 7.2
12.6 9.4
12.2 12.2
(1). Average speed 23.4mph, 20 2 stops per mile, 27.7-mile loop,
multiple tests averaged.
(2) Average speed 36.7 mph, 0.36 stops per mile, 18.4-mile loop,
multiple tests averaged.
(3) Supplementary data:
Fuel economy during 20, 000 miles of consumer-tupe usage by
California ARE was 11. 34 mph, with air conditioner in normal use.
(4) Reference ( 16 ).
A-46
-------
APPENDIX A-7
ANALYTICAL, METHOD FOR PREDICTING THE
EFFECT OF VEHICLE WEIGHT ON EMISSIONS
A-47
-------
In this appendix an analytical method is developed to predict
the effect of vehicle inertia weight on emissions starting from knowledge
of the engine emissions (gm/hr) as a function of load (HP) and engine
RPM, vehicle characteristics (weight, frontal area, drag coefficient,
rolling resistance, axle ratio, etc.). an
-------
(HP) road -
- I .
0668 WV -— + .0039 C A V3
+ VW (K + K., V)
i
where
W = Vehicle weight (Ibs. )
2
C A =• Drag coefficient and front area (ft ) of the vehicle
D, F
V E Speed (mph)
dV = Acceleration (mph/sec)
dt
V - Average of the velocity cubed
K , K =• Constants in the rolling resistance equation
1 C*
Equation (1) was evaluated for four vehicles of interest in the present
program. The four cases and the associated constants are given below:
Case
1
2
3
4
Vehicle
Pick-up Truck
Van
Stop-Van
Passenger Car
CD
. 5
.65
.65
.45
AF (ft2)
29
34
44
21
Kl
. 015
. 015
. 014
. 017
K2
. 00026
. 00026
. 00022
. 000334
The vehicle frontal areas were obtained from reference to manufacturer's
sketches of vehicle shapes.
A-50
-------
It is desired to calculate a mean horsepower for both
acceleration and cruise modes appropriate to the LA-4 driving cycle. In
order to do this, one requires
V
dV
dt
V-
average velocity in the mode
average acceleration in the mode
average of the velocity cubed in the mode
Such information is conveniently summarized in Reference (23). For the
present work, the 5-city composite results are used as they compare quite
closely to the LA-4 cycle. Distribution of total time in mode categories
data are given below while acceleration and velocity mode data is given
in Figures A-2. 1 and Table A-7. 1.
% Total time, idle
% Total time, cruise
% Total time, acceleration
% Total time, deceleration
5-City
Composite
12.87
31.83
29.08
26.23
N. Y.C.
17.45
26.49
29. 12
26.95
LA-4
13. 56
27.25
31.73
27.49
A-51
-------
TABLE A-7. 1
COMPACTED NORMALIZED TOTAL TIME MATRIX FOR 5-CITY COMPOSITE (Reference 23)
Initail
Speed, FINAL SPEED, MPH
MPH 0 5 10 15 . 20 25 30 35 40 45 50 55 60 65
0 13.060 0.582 0.559 0.668 1.025 1.891 2.631 2.314 1.321 0.501 0.140 0.052 0.018 0.010
5 0.577 0.746 0.283 0.253 0.299 0.442 0.506 0.427 0.236 0.092 0.028 0.012 0.006 0.002
10 0.419 0.287 0.768 0.345 0.422 0.546 0.519 0.381 0.141 0.051 0.021 0.013 0.007 0.005
15 0.505 0.207 0.303 0.941 0.509 0.589 0.542 0.425 0.244 0.091 0.031 0.023 0.018 0.027
20 0.943 0.286 0.298 0.401 1.633 0.878 0.641 0.357 0.167 0.059 0.030 0.023 0.015 0.008
25 1.829 0.454 0.395 0.465 0.725 3.518 1.246 0.541 0.224. 0.083 0.037 0,031 0.024 0.020
30 2.419 0.488 0.441 0.471 0.560 1.136 5.463 1.228 0.354 0.119 0.048 0.038 0.022 0.024
« 35 2.142 0.394 0.349 0.380 0.311 0.493 1.103 5.255 0.857 0.228 0.066 0.030 0.014 0.017
Ul
40 1.267 0.204 0.158 0.182 0.152 0.193 0.318 0.775 3.450 0.483 0.145 0.063 0.028 0.019
45 0.477 0.087 0.064 0.074 0.065 0.072 0.114 0.214 0.443 2.027 0.340 0.134 0.054 0.015
50 0.160 0.026 0.031 0.022 0.027 0.034 0.035 0.059 0.128 0.319 1.535 0.330 0.107 0.040
55 0.085 0.012 0.013 0.011 0.013 0.018 0.023 0.032 0.061 0.109 0.319 1.806 0.324 0.107
60 0.043 0.013 0.006 0.005 0.006 0.007 0.010 0.020 0.020 0.053 0.109 0.323 2.069 0.292
65 0.037 0.014 0.005 0.001 0.002 0.001 0.002 0.008 0.010 0.016 0.031 0.098 0.284 2.291
NORMALIZED MODE MATRIX SUMMARY
Percent Idle = 13. 060
Percent Cruise = 31.502
Percent Acceleration = 29.158
Percent Deceleration = 26. 303
-------
Using the speed-matrix data given in Table A-7. 1, one finds for cruise
conditions (look at the diagonal of the matrix) that
V = 37 (mph)
V3 = 76,700 (mph)3
The average speed for acceleration is taken to be equal to the average
overall speed (26 mph) for the 5-city composite cycle. From Figure A-7. 1
the corresponding mean acceleration is . 8 mph/sec. Fortunately the
dV.
product V /dt does not changemuch as V changes. The velocity data
for the average cruise and acceleraton conditions can be summarized as
below:
dV,
Mode
Acceleration
Cruise
V1 (mph)
26
37
dt (mph/sec) ^.3
.8 25,000
0 76,700
Now that all the input quantities are known, Equation (1) can be evaluated
for a range of vehicle weights. The results are shown in Table A-7. 2.
Note that the horsepower values calculated are those required at the road,
and not at the engine. In order to get the engine horsepower, some assump-
tion must be made regarding the driveline efficiency. In the present work,
the following values were assumed:
A-53
-------
TABLE A-7. 2
ROAD AND ENGINE HORSEPOWERS
FOR ACCELERATION AND CRUISE MODES
Acceleration Mode
Cruise Mode
W Pick-Up
4500 18.6
(24.8)
6000 23.9
(31.9)
8000 31,0
(41.2)
10000 38.1
(50.5)
12000 45.2
(60.2)
52. 3
(69.5)
Top number =
Bottom number =
Values for 4500 Ib
HP
Van
19.9
(26.5)
25.2
(33.4)
32.4
(43.0)
39.5
(52.5)
46.6
(61.8)
53.7
(71.5)
road
Stop-Van
20.6
(27.2)
25.8
(34.2)
32.7
(43.4)
39.7
(52.7)
46.6
(61.8)
53. 5
(71)
hor sepower
Pick-Up
15.3
(16.9)
17.8
(19.8)
21. 1
(23.4)
24.5
(27.2)
27.8
(30.8)
31.0
(34.4)
HP
Van
19.5
<2U6)
22
(24.4)
25. 3
(26.0)
28. 6
(31.7)
31.9
(34.4)
35. 2
(39.2)
Stop-Van
22. 3
(24.8)
24. 5
(27.3)
27. 5
(30.5)
30.4
(33.6)
33.4
(37.2)
36.4
(40.5)
engine horsepower
. passenger car
Acceleration Mode
18. 5
(24.7)
Cruise Mode
14. 0
(15.5)
A-54
-------
Mode Type of Transmission Driveline Efficiency (
Acceleration
(2nd gear)
Cruise
(3rd gear)
Manual
Automatic
Manual
Automatic
87%
75%
98%
90%
The engine horsepower values are shown in ( ) below the road horsepower
values in Table A-7. 2.
The engine RPM is related to the wheel RPM by the simple relation
Eng. RPM = (Wheel RPM) (GR)
•where
GR = (AX R) (Trans. GR)
wheel RPM = 11.7 V, Wheel rad. = 1. 2*
For the two modes of interest, the following axle and gear ratios were
used.
Car Truck
Mode
Acceleration
C rui s e
The corresponding
Mode
Acceleration
Cruise
Ax R
3.0
3.0
engine RPM
Velocity
26
37
Trans. GR Ax R
1.6 4.1
1 4. 1
are given below:
Eng. RPM
Car
1450
1300
Trans. GR
1.6
1
Truck
1970
1770
Now one is ready to proceed to calculate the emissions.
A-55
-------
It is assumed that all the vehicles of interest are powered by a
V-8, 350 CID engine and have an automatic transmission. Engine dynamometer
emissions data for this engine are given in Reference (22) (designated as 2-3
in that report). Unfortunately, the test cycle included only 1200 and 2300
RPM as shown in Figures A-7.2-4. Intermediate RPM were faired in
following the general shape of two bounding data curves. The general
approach was to calculate the difference between the emissions from a
truck of weight I and a reference passenger car of weight 4500 having
the same engine. The emissions from the reference passenger car for the
LA-4 driving cycle are well known from emissions tests. It is assumed
that the trucks are tested in the same LA-4 driving cycle. Hence the total
cycle time is 23 minutes and the length of the route is 7. 5 miles. Now the
incremental emissions from a truck can be written as
E = HC, CO, NO
car J 7.5 mi.
(2)
Equation (2) is applied for both the acceleration and the cruise mode.
GM E/hr is obtained from Figures A-7. 2-4 using the appropriate values
of HP and Eng. RPM. Table A-7. 3 shows a typical set of calculations for
the Van-truck.
The computed results are compared with the previous baseline
correlation as a function of vehicle weight in Figures A-7. 5-7. In the case
of HC and NO the prediction procedure does surprisingly well both in
X*
accounting for the effect of vehicle weight and in giving a reasonable estimate
of the initial value at I = 4500 Ibs. In the case of CO, both the trend
w
A-56
-------
TABLE A-7. 3
EMISSIONS CALCULATIONS FOR A VAN TRUCK
Engine - 8 cylinders - 350 CID
Acceleration Mode
I
w
4500
car
6000
8000
10000
12000
14000
HP
26. 5
24. 5
33.4
43. 0
52. 5
61.8
71. 5
(E) xv-
A
(E) ^
CO
215
190
275
365
550
860
1200
gm/hr
gm/mi
Eng. RPM
A
CO
3.2
2. 83
4. 1
5.45
8.2 1
12.8 1
18.0
= 1900
HC
49
48
50
64
08
76
228
A
HC
.73
.715
.745
.95
1.60
2. 53
3. 38
NO
X
210
180
310
490
670
770
860
A
NO
X
3. 14
2.69
4.63
7. 3
10.0
11.5
12.8
Cruise Mode
I
w
4500
car
6000
8000
10000
12000
14000
HP
21
15
24
26
31
34
39
A.
.6
. 5
.4
.0
.7
.4
.2
E =
CO
150
120
165
175
260
300
400
(A E)
Eng. RPM = 1400
A A
CO HC HC
2.
1.
2.
2.
4.
4.
6.
42
93
66
82
2
85
4
accel +
73
67
75
75
82
88
100
(A E)
1
1
1
1
1
1
1
.08
.0
.13
. 13
.23
.32
.61
NO
X
160
100
185
210
285
330
415
A
NO
X
2.
1.
2.
3.
4.
5.
6.
58
61
98
38
6
35
7
cruise
A-57
-------
with I and initial value are much less than the previous prediction. The
large discrepancies in the CO results are probably due to cold start effects
and the fact that the mean horsepower approach does not account for time
spent near rated horsepower where the specific emissions are very high.
A-58
-------
- 0.40
- 0.35
- 0.30
- 0.25
- 0.20
- 0.15
- 0.10
LU
I-
cc
H
O
tr
LLJ
u
u
100
10 1 0.1 0.01
PERCENT OF ACCELERATIONS AT A FASTER RATE THAN SHOWN
Figure A7.1 DISTRIBUTION FUNCTIONS OF 5-CITY-COMPOSITE ACCELERATIONS
AT VARIOUS INSTANTANEOUS SPEEDS
A-.59
-------
350
300
250
I 200
o"
X
150
100
50
20
40
60
HORSEPOWER
80
100
120
Figure A-7.2 HC ENGINE EMISSIONS (EXPERIMENTAL)
-------
1500
1000
D)
o"
u
500
20
40
HORSEPOWER
Figure A-7.3 CO ENGINE EMISSIONS (EXPERIMENTAL)
-------
1500
1000
en
500
2300 RPM
1200 RPM
20
40 60
HORSEPOWER
80
100
Figure A-7.4 NOX ENGINE EMISSIONS (EXPERIMENTAL)
-------
-TRUCK
8. 350 CID
IW-INERTIA WT, K-LB
Figure A-7.5 COMPARISON OF PREDICTED AND MEASURED HC EMISSIONS AS A
FUNCTION OF VEHICLE INERTIA WEIGHT
-------
100
90
80
70
E
en
8 60
50
40
30
20
VAN-TRUCK
V-8. 350 CID
PREDICTED INITIAL VALUE
10
IW-INERTIA WT, K-LB
12
14
16
Figure A-7.6 COMPARISON OF PREDICTED AND MEASURED CO EMISSIONS AS A
FUNCTION OF VEHICLE INERTIA WEIGHT
-------
0>
12
IW-INERTIA WT, K-LB
Figure A-7.7 COMPARISON OF PREDICTED AND MEASURED NOX EMISSIONS AS A
FUNCTION OF VEHICLE INERTIA WEIGHT
A-65
-------
APPENDIX A-8
DETAILED DESCRIPTION OF THE MEDIUM
DUTY TRUCK EMISSIONS AND COST
PROGRAM (AMTEC)
A-67
-------
As discussed in Section 2. 7. 3, a computer program (AMTEC)
was written to analyze the costs and benefits of various control strategies
for reducing medium duty truck emissions. In this appendix the computer
program is described in detail and the input information used in typical
calculations documented. A Fortran listing of the program is also included.
The medium duty truck population consists of vehicles of
various ages, weights and shapes, engine types and emission control
systems. For the purposes of calculation, the medium duty vehicles are
divided into m categories (groups) with each group being delineated by
weight/and or usage. In the present calculations, four groups (m = 4)
(1) 6, 000 - 10, 000 Ib trucks
(2) 10, 000 - 14, 000 Ib trucks
(3) 6, 000 - 10, 000 Ib motor homes
(4) 10, 000 - 14, 000 Ib motor homes
were considered. In order to further characterize vehicles within each
group, it is necessary to specify the type of engine and, if any, the emission
control system used. Type of engine designates general classes such as
conventional gasoline, diesel, CVCC, etc. Differences in engine size
(CID), if included in the vehicle characterization, would be accounted for
by introducing additional vehicle groups. For example, 6,000 - 10, 000 Ib
trucks with V-8, 360 CID engines and 6, 000 - 10, 000 Ib trucks with V-8,
A-69
-------
454 CID engines would be treated as separate vehicle groups. Hence the
program has the flexibility to consider different engines and sizes as well
as different control systems.
The exhaust emissions can be expressed in terms of the
baseline emissions for the vehicle /engine combination and the effectiveness
of the control system used. Hence for the Jtn pollutant (HC, CO, NO )
the emissions (gm/mi) from a vehicle in group N can be written as
TEM J (N.Yr I, k.) RJ (k., i)
where
TEMJ (N,YrI,.k) = emissions (gm/mi) of the Jth
pollutant from a vehicle of group N of model year
Yrl having engine type k
f-K
R J (k , i) = emission reduction factor for the J
pollutant using the i control system on engine
type k
fH
The emissions of the J pollutant for all the vehicles of group N during
the year Yr can be calculated by summing over the model years from
1950 to the year Yr.. Thus
emJ (N, Yr) = K. SALE (N, Yrl) FREM (N, Yr - Yrl)
Yrl = 1950
FRE (N, Yr I, k ) TRAV (N, Yr - Yr I)
1
TEMJ (N, "fir I, k ) RJ (k , i
A-70
-------
where
SALE (N, Yrl) = Sales of the Nth group of vehicles in
the model year Yrl
FREM (N, Yr -Yr I) = Fraction of vehicles in group N
remaining on the road after (Yr -Yr I)
years
FRE (N, Yr I, k ) = Fraction of sales of vehicles in group
N in model year Yr I having engine
type k
TRAV (N, Yr - Yr I) = miles traveled per year by vehicles
in group N of age (Yr - Yr I)
K = conversion factor for emissions in grams to emissions
in tons.
The total emission of the J pollutant in the year Yr is then obtained
by adding up the contributions of all the groups N. Thus
m
where
EMTJ (Yr) = emJ (N, Yr)
N=l
EMTJ (Yr) = total emission of the Jth pollutant from all
the medium duty vehicles on the road in
year Yr.
m = number of vehicle groups considered.
A-71
-------
The fuel consumed in the year Yr is computed for each vehicle
group and engine type using the expression
Yr
KFUN (N, Yr, k ) = £" SALE (N.Yrl)FREM (N.Yr -Yrl)
Yrl
where
D
0
FRE (N, Yrl, k ) TRAV (N, Yr - Yr
MPG (N, k )
1 + FP (k
,„]
KFUN (N, Yr, k ) = fuel consumed by the vehicles in the
f H
Ncn group in the year Yr having engine
type k
M PG (N, k )
Fuel economy (miles per gallon) of
vehicles in N group having engine
type k
FP (k, i)
Fuel penalty for the i control system
used on engine type k
The total fuel consumed in year Yr by engines of type k is
KFU (Yr, k) = Z KFUN (N, Yr, k)
N=l
The incremental fuel consumed by the engine type k due to the use of
control systems and/or alternator engines is calculated from
A-72
-------
A KFUN (N, Yr, k) = KFUN (N, Yr, k)
Yr
*••
2. (SALE)(FREM) (FRE) ~ (FF(k))
YJ.T jyiJrVj
where
^ KFUN (N, Yr, k) = incremental fuel consumed due to
emission control by the vehicles in
group N with engine type k
FF (k) = fuel factor relating baseline fuel economy of the
alternate engine k and the conventional gasoline
engine.
The incremental fuel consumed in year Yr by engines of type k is
given by
m
A KFU (Yr, k) = ^ KFUN (N, Yr, k)
N = 1
where
A KFU (Yr, k) = incremental fuel consumed in the year Yr
by engines of type k due to emission
control strategies
The incremental costs associated with a specified emission
control strategy, both the use of control systems and alternative engines,
can be calculated from the following relation:
A-73
-------
. m
COST (Yr) = £ A KFU(Yr, k) GASCST (k)
k = 1
m n
S(N, Yr) FRE (N, Yr, k) 1C (k, i)
N=l k = 1
m Yr n r"
+ < £ <; IS (N, Yrl) FREM (N, Yr-YrI)
N=l Yrl k=l
=1950 T
FRE (N,YrI,k)MC (k,i)J
where
COST (Yr) = total incremental cost in the year Yr associated
with emission reduction
GASCST(k) 2 cost ($/gal) of the fuel for engines of type k
1C (k, i) = incremental initial cost of engine type k with
control system i
MC (k, i) ~. incremental maintenance cost of engine type k
with control system i
The maintenance cost MC is made up of two parts:
MC = (MC), + (MCL
1 Z
where
(MC) r annual maintenance cost independent of mileage
(MC) - catalyst maintenance cost dependent on mileage
A-74
-------
Selected input data needed to obtain the results discussed in
Section 2. 7. 4 are listed in the Tables A-8. 1 with the sources for the data
indicated. The remainder of the input data required is given elsewhere in
the report as summarized in Table 2.24.
A typical output from the AMTEC program is shown in Table
A-8. 2. Graphical presentations of a series of computer runs (Table 2. 25)
are given in Figures 2. 19-25.
A-75
-------
N=l
SALES
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
19oO
1961
1962
1963
1964
19t5
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
I960
1961
1962
1983
1984
1985
1986
1967
1968
1989
FOR EACH YEAR BY VEHICLE TYPE
266000.
260000.
235000.
222000.
187000.
213000.
209000.
160000.
127000.
176000.
183000.
180000.
213000.
246000.
250000.
289000.
292000.
281000.
373000.
383000.
372000.
397000.
451JOO.
459000.
490000.
535000.
569000.
608000.
649000.
689000.
733000.
773000.
813000.
853000.
893000.
933000.
973000.
1013000.
1053000.
1093000.
89000.
99000.
50000.
47000.
39000.
47000.
40000.
37000.
14000.
14000.
12000.
11000.
9000.
6000.
6000.
5000.
8000.
5000.
5000.
t>000.
t>000.
6000.
6000.
6000.
6000.
6000.
6JOO.
6000.
6000.
600U.
6000.
6000.
6000.
6000.
6000.
6000.
6000.
6000.
c.000.
6000.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
5000.
6000.
9JOO.
13000.
22000.
29000.
47000.
80000.
42000.
80000.
80000.
81000.
80000.
81000.
81JOO.
82000.
82000.
82000.
62000.
82000.
82000.
82000.
62000.
82000.
82000.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
1CCO.
10CO.
10000.
38CCO.
94000.
97000.
101000.
104000.
108000.
112000.
116000.
119000.
123000.
127000.
131000.
135000.
139000.
143000.
147000.
151000.
155000.
TABLE A-8. 1 Input Sales Data
A-76
-------
FREM
TRAV
N=l
AGE
1
2
3
4
5
6
7
a
9
10
ii
12
13
14
15
16
17
18
19
20
21
Ref
0.994
0.974
0.961
0.940
0.909
0.872
0.83ti
0.791
0. 745
0.686
0.625
0.558
0.487
0.403
0.325
0.243
0.163
0.080
0.0
0.0
0.0
(36)
AGE
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
11000.
10800.
10700.
10500.
10300.
10000.
9800.
9600.
9500.
9200.
9000.
8700.
8500.
8300.
8100.
790U.
7700.
7400.
7100.
6800.
6300.
5900.
5300.
4800.
4200.
3400.
2400.
0.
0.
11000.
10800.
10700.
10500.
10300.
10000.
9800.
9600.
9500.
9200.
9000.
8700.
8500.
8300.
8100.
7^00.
7700.
7400.
7100.
6800.
6300.
5900.
5300.
4800.
4200.
3400.
2400.
0.
0.
5500.
5400.
5300.
5200.
5100.
5000.
4900.
4800.
4700.
4600.
4500.
4300.
4200.
4100.
4000.
3900.
3800.
3700.
3500.
3400.
3100.
2900.
2600.
2400.
2100.
1700.
1200.
0.
0.
550C.
54CO.
5300.
5200.
5100.
5000.
4900.
4800.
4700.
4600.
4500.
4300.
4200.
4100.
4000.
3900.
3800.
3700.
3500.
3400.
3100.
29GO.
26CO.
240C.
2100.
1700.
1200.
C.
0.
Ref (37)
TABLE A-8. 1 (cont) Input Vehicle Operation Data
A-77
-------
Control
System , ? fl) (21
0 l 2 3 45 6 78 9( 10
THREE INITIAL COST LEVELS (ROW»tLOWtNOMINAL,AND HIGH FOR EACH CONTROL SYSTEM (COL.)
0.0 97.00 102.00 161.00. 236.00 190.00 111.00 144.30 112.00 341.03 361.00
0.0 114.0_0_ . 124.00 204.00 295.00 248.00 145.00 173.00 144.00 462.03 492.00
0.0 131.00 146.00 253.00 356.00 307.00 180.00 203.00 176.00 573.00 613.30
_IHAEg LEVELS OF FIXED MAINTENANCE COST FOR EACH CONTROL SYSTEM
0.0 3.00 3.00 8.00 8.00 3.00 3.00 3.00 3.00 3.00 3.00
0.0 3«00 3.00 8.00 8.00 3.00 3.00 3.00 3.00 3.03 3,30
0.6 " 3/66 " 3.00 8.00 8.00 3.00 3.00 3.00 3.00 3.00 3.00
THREE LEVELS OF VARIABLEiREPLACEMENT) MAINTENANCE COST FOR EACH CONTROL SYTEM. REPLACE EVERV25033. MILES
0.0 22.50 22.50 105.00 222.50 121.50 12.50 22.50 22.50 3.0 O.D
0.0 22.50 22.50 1.30.00 272.50 146.50 12.5.0 22.50 22.50 0.0 0.0
> 0.0 22.50 22.50 152.50 317.50 169.00 12.50 22.53 22.50 3.0 0.6
1 THREE LEVELS OF VARIABLEiPART IAL SUBSTITUTION) MAINTENANCE COST FOR EACH COMTROL SYSTEM. SUBSTITUTE EV ER Y.25000. MILES
3o 0.0 22.50 22.50 85.00 175.00 101.50 12.53 22.50 22.50 0.0 0.0
0.0 22.50 22.50 102.50 210.00 119.00 12.50 22.50 22.50 0.0 0.0
0.0 22.50 22.50 120.00 245.00 136.50 12.50 22.50 22.50 3.0 0.0
THREE LEVELS OF VARI A8LE( REPLACEMENT ) MAINTENANCE COST FOR EACH CO_NTRpL_SYSTJ:M. REPLACE FV E* Y.I 333_3 . Jl.l L r S _
0.0 -8.00 -5.00 -5.00 -5.00 -8.00 -5.00 -3.00 1.03 0.0 4.00
0«0 -.8.0.0. -5.00 -5.00 -5.00 -8.00 -5.00 -8.00 1.00 0.0 4.30
0.0 -8.00 -5.00 -5.00 -5.00 -8.00 -5.00- -8.00 1.00 0.0 4.00
(1) Baseline Diesel
(2) Diesel with EGR
TABLE A-8.1 (Cont.) Summary of Input Cost Data
-------
-vl
xD
YEAR
1970
1971
1972
1973
197*
1975
1976
1977
1978
1979
1980
1981
1982
1983
193*
1985
1986
1937
1988
1989
(1)
HC
0.43286
0.4221E
O..4179t
0.41916
0.4253E
0.4176E
0.4119E
0.4074E
U.3680E
0.3682E
0.3465E
0.3229E
0.2976E
0.2742E
0.2531E
0.2342E
0.2173E
0.2029E
0.1909E
0.1807E
06
06
06
06
06
06
"06
06
06
06
06
Ob
06
06
06
06
06
06
06
06
(1)
CO
0.4456E
0.4432E
0.4456E
0.4525E
0.4644E
0.45-fOE
0.4453E
0.4370E
0.4124E
0.3672E
0.3611E
0.3335E
0.3054E
0.2791E
0.2554E
0.2344E
0.2158E
0.2002E
0.1869E
0.1763E
(1)
(2)
(3)
(1)
NO
07 0.2891E
07 0.3083E
07 0.3385E
07 . 0.3742E
07 0.4142E
0? 0.4279E
07 0.4422E
07 0.4565E
07 0.44S9E
07 0.4433E
07 0.4364E
07 0.4294E
07 0.4228E
07 0.4170E
07 0.4121E
07 0.4081E
07 0.4049E
07 0.4032E
07 C.4032E
07 0.4048E
tons /year
gal/year
06
06
06
06
06
06
06
C6
06
06
06
06
06
06
06
C6
06
06
06
06
(2)
GAS
0.3276E 10
0.3460E 10
0.3783E 10
0.4108E 10
0.4482E
0.4926E
0.!>386E
0.5861E
0.6286E
0.6668E
0.6912E
0.7126E
C.7323E
0.7524E
C.7730E
0. 7940E
0.8151E
0.6369E
0.8593E
0.8823E
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
(2)
DEL GAS
0.0
0.0
0.0
0.0
0.0
0.369BE
0.7457E
0.1135E
0.1343E
0.1538E
0.1683E
0.1817E
0.1941E
0.20b!>E
0.2180E
0.2290E
0.2390E
0.2484E
0.2567E
0.2646E
08
08
09
09
09
09
09
09
09
09
09
09
09
09
09
(2)
DIESEL DEL
0.3 0 .
0.0 0.
0.0 0.
0.0 0.
0.0
0.0
0.0
0.0
0.3300E
0. 1011E
0.2681C
0.45SOE
0.6649E
0.8707E
0.1075E
0.1276E
O.l474h
0.1668E
0.18b6E
0.2037E
0.
0.
0.
0.
08 -0.
39 -0.
09 -0.
09 -0.
09 -0.
09 -0.
10 -0.
10 -0.
10 -0.
10 -0.
10 -0.
10 -0.
(2)
DIESEL
0
0
0
0
0
D
0
0
1677E
514U
13t)3F
2333F
33BOI-:
4426t
5465E
6487P
7495E
8473E
94->6P
1036E
08
08
09
09
09
09
09
09
09
09
09
10
(3) (3)
LOw CIST COST
0.0 D.O
0.0 3.0
0.0 0.0
0.0 0.0
0.0
O.S790E
6.1068F
0.1265E
0.1573E
0.1&97E
0.1838E
0.1682E
0.1444E
0. 1158F.
O.HM3F
0.5891E
0. 3084F
0.3517E
-0.?318F
-0.4853E
08
39
39
09
39
09
09
39
09
08
08
08
07
39
08
3.3
0.1056C
0.1272E
3.1499E
0.1951E
3.2114E
(J.2400E
0.2267H
3.2028E
0.1723H
3.1417F
0.1115r-
0.8157C
0.5246E
3.240'tE
-0.2850E
09
09
09
09
09
09
09
09
09
09
0?
03
08
08
07
(3)
HICOST
0.0
0.0
0.0
0.0
0.0
0.1234E 09
0.1477E 09
0.1732E 09
0.2324P 09
0.2560F 09
0.2937E 09
0.2822E 09
0.2580F 09
0.22S3E 09
0.1926E 09
0.1605F. 09
0.1285E 09
0.9746E 08
0.67?OF 38
0.3R64E 08
dollars /year
TABLE A-8.2 Typical Output From AMTEC Program
-------
FORTRAN IV G LEVEL 21
MAIN
DATE = 73151
14/15/42
PAGE 0001
I
00
o
0001
0002
0003
0004
0005
OJ06
0007
0008
OC09
0010
0011
0012
0013
0014
0015
0016
0017
0018
0019
0020
0021
0022
0023
0024
0025
0026
0027
0028
0029
0030
0031
0032
003"5;''
0034
0035
0036
0037
003d
0039
0040
0041
0042
C043
0044
0045
0046
0047
0048
0049
Oo50
0051
DATA GMPTON/907200.0/
DATA THOUS/1000.0/
REAL MPG(5,10)
DIMENSION SALES(40,10 ItREMVI40),EM(4,5,10,40),FRE(40,5,10 It
* TRAV(10,40),FRA(5, 11,401,REMP<4,5,11) ,TEM(4,40),
* IND(10,40),RPLMC(3,ll)tSUBMC(3 til ItFF( 101, FUEL (511
* FUPENU1I ,TOC(3),TOTCST(3,40I,OSTI( 3,11) ,F I XMC( 3,11) ,
* GASCSTO) ,DSLCST(3),COSTI(3,ll),RPL10!3,ll),JNOl10, 40),
*LEM(4)
1000 FORMAT18F10.0)
1001 FORMATI5UO)
1002 FORHAT(I10,2F10.0)
1003 FORMAT!4A4)
1004 FORMAT!11F6.0)
READ(5tlOOU NCASE
READ(5,1003HLEM(L),L = 1,4)
READ (5, 10011 NTtNE.NC
READ(5,1001) IYR,JYR,LYR,IYRC,IYRO
READ (5,1002) MCRS.DISTIO,01ST25
MYR=JYR-IYR*1
NYft=LYR-IYR*1
DO 2 JK=1,NYR
2 READtS,10001 (SALES(Jft,ITI,IT=l,NT)
OU 92 JR=1,NYR
DO 92 IT=1,NT
92 SALES!JR,m=SAL£SUR,m*THOUS
WRITE16.502)
502 FOHMAT12X,'SALES FOR EACH YEAR BY VEHICLE TYPE')
DO 902 JR=l,NYR
KR=IYR+JR-1
902 HR(TE(6,'V002) KR , ( SAL ES( JR , I T) , I T=l , NT )
4002 FORMAT(2X,I5t10F10.0)
JXRP=1
JXR=IYRD-IYR
IF(JXR.Eg.O) GU TO 703
DO 933 JR=ltJXR
DO 933 IT=1,NT
FRE( JR,1 , ID = 1.0
DO 933 IE=2,NE
933 FRE(JR,IE,IT)=0.0
JXRP=JXR*1
703 DO 3 JT=1,NT
DO 3 JR=JXRP,NYR
3 REAO(5,10001 (FRE(JR,IE,JT),IE=1,NE)
DO 803 IT=1,NT
wRITE(6,503l IT
503 FURMAT12X,'DISTRIBUTION OF ENGINE TYPES BY MODEL YEAR FOR VEHICLES
* OF TYPE',13)
DO 903 JR=1,NYR
KR=IYR+JR-1
903 WKITE(6,4003) KR,(FRE(JR , I E , IT ) ,IE=l,NtI
4003 FORMAT12X,I5f10F6.2)
803 CONTINUE
00 4 IE=1,NE
4 READ (5,1000) (MPG11E , IT I,IT = l,NT)
WRITE(6|504)
504 FURMAT12X,'GASOLINE CONSUMPTION (MPG) FOR EACH ENGINE (ROMS) AMD F
*OR EACH VEHICLE TYPE (COLS.)')
o
l-t
3
F
t_l.
CO
rt-
!-*•
3
OQ
H
W
O
-------
FORTRAN IV G LEVEL 21
MAIN
DATE » 73151
14/15/42
PAGE 0002
i
00
0052
0053
0054
0055
0056
0057
0058
0059
0060
C061
0062
0063
0064
0065
0066
0067
0068
0069
0070
0071
0072
0073
0074
0075
0076
0077
007a
0079
0080
0031
0082
0063
0084
0085V
0066
0087
0088
OC89
C090
0091
0092
OJ93
0094
0095
0096
0097
0098
0099
0100
01U1
0102
0103
0104
00 804 IE=1,NE
804 HRITE(6,4004) (MPG(IE,ITI,IT=l,NT)
4004 FORMAT(2X,IOF7.2)
00 5 JR=1,NYR
5 READ(5,1000) (TRAV4 U
*SED ON VEHICLE TYPES (COLS.) BY MODEL YEAR1)
DO 706 JR=1,NYK
KR=IYR»JR-1
706 HRITE(6,4006» KR,(EMIL,IE,IT , JR>,IT=1,NT)
4006 FORMAT(2X,I5,IOF6.1)
806 CONTINUE
906 CONTINUE
READ(5,1000) (REMV(JR),JR=1,NYRI
WRITE16.507)
507 FORMAT(2X,'FRACTION OF VEHICLES STILL OPERATINGtAS A FUNCTION OF A
*GE't/i2X,« AGE ')
DO 907 JR=1,NYR
HRITEI6.4007) JR, REMV(JR)
4007 FORMAT(2X,I5,F7.3)
907 CONTINUE
DO 8 L=l,3
DO 8 IC=1,NC
8 REAO(5,1000» {REMPIL,IE,1C),IE=1,NEI
DO 908 L=l,3
KKITE(6,50BI LEM(L)
508 FORMAT(2X,'REMAINING«tA4,'EMISSION (FRACTION) WHEN USINS CONTROL D
*EVICE (ROW) ON EACH ENGINE TYPE (COLS.)')
DO 808 IC=l,NC
808 WRITEI6,40081 (REMPtL,IE, 1C),IE=11NE)
4008 FORMATI2X.10F8.2)
908 CONTINUE
DO 10 JJ=1,3
10 READ(5,1000) (COST I(JJ11C ItIC=1,NC)
HKITE(6,510I
510 FURMATI2X,'THREE INITIAL COST LEVELS (ROW),LOW,NOHINALtAND HIGH FO
*R EACH CONTROL SYSTEM (COL.) ')
00 910 JJ=1,3
910 WRITE(6,4010) (COST I(JJ,1C),IC-1,NCI
4010 FORMAT(2XillF10.2>
DO 11 JJ=lt3
11 READ(5,10001 (FIXMCIJJ.1C)»IC=l,NCI
-------
FORTRAN IV (i LEVEL 21
MAIN
OATE = 73151
14/15/42
PAGE 0003
oo
N)
0105
0106
0107
0108
0109
QUO
0111
0112
0113
0114
0115
0116
0117
0118
0119
0120
0121
0122
0123
0124
0125
0126
0127
0128
0129
0130
0131
0132
0133
013*
0135
0136
01 *7
0138
0139
0141)
0141
0142
0143
0144
0145
0146
0147
0148
0149
0150
0151
0152
0153
0154
0155
WRlTE(6t511l
511 FORMATI2X,'THREE LEVELS OF FIXED MAINTENANCE COST FOR EACH CONTROL
* SYSTEM')
DO 911 JJ=1,3
911 HRITE<6,4011) (FIXMCIJJ,IC),IC=1,NC)
4011 FORMAT(2X,11F10.21
DO 12 JJ=1,3
12 READ15,10001 (RPLMCIJJ.1C),IC=1,NC)
WRITEI6.512I DIST25
512 FORMAH2X,'THREE LEVELS OF VARIABLE(REPLACEMENT) MAINTENANCE COST
*FOR EACH CONTROL SYTEM. REPLACE EVERY',F6.0,• MILES')
DO 912 JJ=lt3
912 MRITE(6>4012) (RPLMC(JJ,1C),IC=1,NC)
4012 FORMAT(2X,11F10.2»
DO 13 JJ=1,3
13 READ(5,1000) (SUBMC(JJ , 1C)>IC= li NC )
WRITEI6.513) OIST25
513 FORMAT(2X,'THREE LEVELS OF VARIABLE(PARTIAL SUBSTITUTION I MAINTENA
*NCE COST FOR EACH CONTROL SYSTEM. SUBSTITUTE EVERY',F6.0f' MILES')
DO 913 JJ = U3
913 WRITEI6,40131 (SUBMC(JJ,1C)tIC=l,NC)
4013 FORMAT(2X,11F10.2I
00 14 JJ=1,3
14 READ «5i10001(RPL10«JJ,1C)tIC=1tNC»
WRITEC6.514) D1ST10
514 FOKMATJ2X,'THREE LEVELS OF VARIABLE(REPLACEMENT) MAINTENANCE COST
*FOR EACH CONTROL SYSTEM. REPLACE EVERY',F6.0t« MILES')
DO 914 JJ=lt3
914 KRITE(6,4014) (RPL10(JJ11C)t IC=ltNC)
4014 FORMAT(2X,11F10.2I
READ(StlOOO) ,4054)
4054 FORMAT(2X,'FUEL PENALTY (GAIN,IF NEGATIVE) FOR USING EACH CONTROL
*SYSTEM'I
WRITE(6,954) (FUPEN(IC),IC=1,NC)
954 FURMAT!2X,UF6.2>
REAOI5.1000I (FF(IEI,IE=1,NE)
HRITE(6,40551
4055 FORMAT(2X,'FUEL ADJUSTMENT FACTORS BY VEHICLE TYPE'I
WRITE(6,1955> I FF( IE ) , I E=1 ,NEI
1955 FORMAT(2X,10F6.2)
-------
FHKTAAN IV G LEVEL 21
MAIN
DATE - 73151
14/15/42
PAGE 0004
oo
oo
0156
0157
015a
0159
0160
0161
0162
0163
0164
0165
0166
0167
0168
0169
0170
0171
0172
0173
0174
0175
0176
0177
0178
0179
0180
0181
0182
0133
0184
0185
0186
0187
0188
0189
0190
0191
0191:
0193
0194
0195
0196
0197
0198
0199
0200
0201
0202
0203
0204
0205
0206
0207
0208
0209
0210
0211
HRITE<6,520I
520 FORMATJ2X,'VEHICLE POPULATION BY YEAR1I
DO 20 JR=1,NYR .
ONROAD=0.0
JXRZ=IYR*JR-1
DO 19 IT=liNT
DO 19 J=1,JR
1AGE=JR-J+1
19 UNRUAD=ONROAD*SALESCJ,ITI*REMV(IAGEI
ONROAD=r!NROAD/THOUS
WRITE(6,4020) JXRZ.ONROAD
4020 FORMAT(2X,UO,F10.0»
20 CONTINUE
DO 26 IT=1,NT
0=0.0
DU=0.0
DO 25 IAGE=lfNYR
D=D+TRAV(IT,IAGE)
DO=DO+TRAV(IT,IAGE)
J=D/DIST25
K=OD/DIST10
IF(J.EQ.O) GO TO 22
INDI1T,IAGE)=1
0=U-J*OIST25
GO TO 23
22 INDIIT,IAGE)=0
23 IFIK.EQ.OI GO TO 24
JN01IT,IAGEI=1
DO=00-K*OIST10
GO TO 25
24 JND
-------
FOKTRAN IV 6 LEVEL 21
MAIN
DATE = 73151
U/15/42
PAGE 0005
>
I
00
0212
0213
0214
0215
0216
0217
0218
0219
0220
0221
0222
0223
022*
0225
0226
0227
0228
0229
0230
0231
0232
0233
0234
0235
0236
0237
0238
0239
0240
0241
0242
0243
0244
0245
0246
0247,.
0248''
0249
0250
0251
0252
0253
0254
0255
0256
0257
02.58
0259
0260
0261
0262
0263
0264
0265
0266
0267
0268
DO 400 JR=MYR,NYR
00 70 L=l,3
SUMIC=0.0
DO 60 IC=1,NC
SUMIE=0.0
DO 50 IE=1,N£
SUMJR=0.0
DO 40 J=1,JR
IAGE=JR-J+1
SUMIT=0.0
DO 30 IT=1,NT
30 SUM! T=SUMIT+SALES(J,IT»*REMV(IAGE)
40 SUMJR=SUMJR+SUMIT*FRA(IE,IC, Jl
**FRE(J,IE,IT)
50 SUMIE=SUMIE*REMP(L,IE,IC)*SUMJR
60 SUMIC=SUMIC+SUMIE
70 TEH(L,JR1=SUMIC/GHPTON
80 CONTINUE
FUG=0.0
FUO=0.0
DFUG=0.0
DFUD=0.0
DO 130 IE=1,NE
JF=FUEL( IEI
SUMITA=0.0
SUMITB=3.0
DO 120 IT=1,NT
SUMJA=0.0
SUHJB=0.0
00 L10 J=1,JR
*EM(L,IE,IT,J)*TRAV( IT,I AGE)
A=SALEStJ,IT)*REMV(IAGE)*FRElJ,IE,IT)*T«AV(IT,IAGE»/MPG(IE,ITI
SUMICA=0.0
SUMICB=0.0
DO 100 IC=1,NC
SUMICA=SUMICA*A*FRA(IE,IC,JI*«1.0*FUPEN( ICM
100 SUM1CB=SUMIC8*A*FRA( I E , 1C , J> /FF ( IE )
SUMJA=SUMJA+SUMICA
110 SUMJB=SUMJB+SUMICa
SUMITA=SUMITA+SUMJA
120 SUHITB=SUM1TB+SUMJ8
GO TO <124,126I,JF
124 FUG=FUG»SUMITA
DFUG=DFUG*SUMIT8
GO TO 130
126 FUD=FUD*SUMITA
DFUO=DFUO*SUMITB
130 CONTINUE
DFUG=FUG-DFUG
DFJD=FUD-DFUD
00 350 JJ=1.3
DO 150 J=l,3
ISO TOC(J)=0.0
DO 230 IC=1,NC
SUMIE=0.0
DO 220 IE=1,NE
SUMIT=O.O
DO 210 IT=1,NT
-------
FORTRAN iv o LEVEL 21
MAIN
DATE = 73151
14/15/42
PAGE 0006
i>
i
oo
(J1
0269
0270
0271
0272
0273
0274
027b
0276
0277
0278
0279
0280
0<:8l
0282
0283
0284
0285
0286
0287
02B8
0289
0290
0291
0292
0293
0294
0295
JR
= SALESU,ITI*FREU,IE,1TI*FRA(IE,IC,J»
210 SUMIT=SUMIT+SUMJ
220 SUMIE=SUMIE*SUMIT
OSTt (JJi ICI=SUM1E*COSTI(JJ,IC)
230 TOC(JJ)=TOC( JJI+OSTK JJtIC)
DU 330 J=ltJR
IAGE=JR-J»1
SJMIC=0.0
00 320 IC=1,NC
SUH1T=0.0
DO 310 IT=1,NT
SUMIE = 0.0 ,•
UO 300 IE=1,NE
300 SUMl E = SUMie«-SALES(Jt !T)*FREIJf IE, IT)*FRA(IE, 1C , J I*REMV( I AGE )
A=FIXMC( JJt IC)*INDUT,IAGEI*(RPLMC(JJiiC)*MCRS*SUBHCUJ,IC)*
*ll-MCRS) H-JND(IT,IAGE)*RPL10(JJtlC)
310 SUMIT=SUHIT+SUMIE*A
320 SUMIC=SUMIC+SUMIT
330 TOTCST( JJ,JRI=DFUG*GASCST(JJ)*DFUD*DSLCST(JJ)+TOCUJ»*SJMIC
350 CONTINUE
JX=JR-1*IYR
WRITE (6t 2001) JXt (TEM(L,JRI ,L = 1,3) t FUG, 0 FUG, FUD, DFUDt ( T3TCSTC J Jt JR
*l,JJ=l,3t
2001 FORMATdXtUf 10E12.4)
400 CONTINUE
410 COiNTINUE
STOP
END
-------
APPENDIX A-9
GRAPHICAL SUMMARY OF BASELINE
EMISSIONS DATA VERSUS INERTIA WEIGHT
A-87
-------
MDV BASELINE HC EMISSIONS vs INERTIA WEIGHT
(MEASURED ON MODIFIED 1975 LDV FTP)
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
135 DATA POINTS - ALL 1970-73
TRUCKS AND MOTOR HOMES
(EXCLUDING 1973 CALIF.
VEHICLES) (INCLUDING BOTH
. TUNED & UNTUNED VEHICLES)
NOTE: THE LINES CONNECT DATA
POINTS FROM THE SAME
VEHICLE TESTED AT
SEVERAL Iw's.
10
( •) - TRUCK
(X ) - MOTOR HOME
10
Figure A-9.1 INERTIA WEIGHT (1000 LBS)
A-89
-------
MDV BASELINE CO EMISSIONS vs INERTIA WEIGHT
(MEASURED ON MODIFIED 1975 LDV FTP)
200
190
180
170
160
150
140
130
120
^ 110
O inn
90
80
70
60
50
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35 DATA POINTS - ALL 1970-73
FRUCKS AND MOTOR HOMES
EXCLUDING 1973 CALIF.
/EHICLES) (INCLUDING BOTH
FUNED & UNTUNED VEHICLES)
JOTE: THE LINES CONNECT DAT/
POINTS FROM THE SAME
VEHICLE TESTED AT
SEVERAL Iw's.
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Figure A-9.2 INERTIA WEIGHT (1000 LBS)
A-90
-------
MDV BASELINE NOX EMISSIONS vs INERTIA WEIGHT
(MEASURED ON MODIFIED 1975 LDV FTP)
£M
19
18
17
16
15
14
13
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35 DATA POINTS - ALL 1970-73
RUCKS AND MOTOR HOMES
EXCLUDING 1973 CALIF.
EHICLES) (INCLUDING BOTH
UNED & UNTUNED VEHICLES)
OTE: THE LINES CONNECT DATA
POINTS FROM THE SAME
VEHICLE TESTED AT
SEVERAL Iw's.
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-------
APPENDIX B-l
Catalytic Converter Cost and Production Lead Time
Introduction and Summary
Schedules submitted to the EPA and Aerospace Corporation by catalyst
and substrate suppliers are shown in Figure B.I. The operations considered in
estimating the lead times are design, engineering, construction of new
facilities, installation of equipment, and production build up.
The corresponding sets of data from the catalyst and substrate
suppliers are found to be in agreement. It can readily be seen that the lead
times estimated to be required by the various substrate suppliers vary in a
range from 12 to 24 months while catalyst suppliers vary from 20 to 24 months.
The differences in lead time may be due to varying degrees of optimism in
estimating the facility construction and equipment schedule. From Figure B.I,
and allowing for the fact that production catalysts must be available at the
manufacturers plant in advance of first vehicle production, the automotive
manufacturer lead time requirement would be expected to be approximately
2 years.
In general, the agreement in catalytic converter production mile-
stones among various automotive manufacturers is good. Among all the
automotive manufacturers represented the overall lead time requirement ranges
from 24 to 28 months. This is due primarily to the fact that the converter
represents a new technology, and involves a source of supply that the
automotive industry is unfamiliar with in high-volume production. Thus, the
lead time requirement includes the uncertainties associated with new vendor
associations. The overall production lead time schedules for the major
automobile manufacturers are shown in Figure B.2. It could be concluded that
there are no gross inconsistencies among or between the lead time specifications
of the suppliers and manufacturers.
B-l
-------
CATALYST SUPPLIERS
ENGLE HARD
w
OXY-CATALYST
MATTHEY BISHOP
W.R. GRACE
MONSANTO
SUBSTRATE SUPPLIERS
CORNING GLASS
REYNOLDS
KAISER
MT NO. 1
MT NO. 2
P
(PELLET)
(MONOLITH)
PRODUCTS
X (ALC» °\
CONSTRUCTION & INSTALLATION UP*""
''ENGIN.8' CONSTRUCTION & INSTALLATION UP*"1"
DiNGIN.* CONSTRUCTION & INSTALLATION I^CKOU?
"IS81 CONSTRUCTION & INSTALLATION CHECKOUT
DESIGN & CONSTRUCTION ft INSTALLATION C^ECKOU?
D|NG3|N& CONSTRUCTION & INSTALLATION CHECKOUT
DESIGN & rflNTRUCTION ft INSTALLATION STARTUP &
ENGIN. OUIMIHUCIIUIM & IIMblALLMIIUlM CHECKOUT
D|wi?i')fi8' CONSTRUCTION & INSTALLATION rwprTfnnT
CiMullM. l^riCUIVLIU 1
•NG^N & CONSTRUCTION
IN'GIN & CONSTRUCTION & INSTALLATION CHECKOUT
DESIGN & CONTRUCTION 8, INSTALLATION STARTUP &
ENGIN. CONTRUCTION & INSTALLATION CHECKOUT
DESIGN ft CONSTRUCTION & INSTALLATION S^CKOUT
1 1 1 1 1 1 1 | | 1 1 1 1
2 46 8 10 12 14 16 18 20 22 24 26
MONTHS
Figure B.1 PRODUCTION LEAD TIME SCHEDULES FOR CATALYST AND SUBSTRATE SUPPLIERS
-------
AUTOMOTIVE MANUFACTURE
AMERICAN
CHRYSLER
FORD
G. M.
VOLVO
VOLKSWAGEN
CO
F
C
F
A C D E
F
A B C D E
F
A B E
F
AC D E
F
B D
8 10 12 14 16 18 20 22 24 26 28
MONTHS
A - PRODUCTION DESIGN & PRELIMINARY APPROVAL
B - TOOLING AND FACILITIES PROGRAM APPROVAL
C - FACILITIES AND LONG LEAD TIME PARTS/EQUIPMENT
D - DURABILITY AND CERTIFICATION TESTS
E - VEHICLE PILOT PART PROGRAM
F - START VEHICLE PRODUCTION
Figure B.2 PRODUCTION LEAD TIME SCHEDULES FOR CATALYTIC CONVERTERS
(DATA SUPPLIED BY AUTOMOBILE MANUFACTURERS)
-------
One of the most pressing issues concerning catalytic converters is
the use and supply of noble metals. Those considered are platinum and
palladium at a cost of $130/troy ounce and $40/troy ounce respectively. The
estimated usage of platinum per converter runs anywhere from 0.03-0.1 troy
ounce, i.e. a cost of $4-$13. The final price of a complete converter package
may range from $10 to $50 for light duty vehicles. This price would depend
on many factors; the amount of noble metal used, substrate, and the final
configuration of the converter.
To date Ford Motor Company is the only automotive manufacturer
that has made a commitment to a catalyst supplier. Their contract with
Engelhard Industry for supplying catalyst has provided financial backing of
up to $4.9 million for facilities and equipment. Ford also has made purchase
commitments with American Lava. The lead time for the development of these
supplier facilities is about 24 months.
Discussion
Catalytic converters primarily consist of a catalytic material
such as a base or noble metal or some combination of the two. Noble metals
seem to be the choice since performance is much better although the cost is
considerably higher. The noble metals being considered are platinum and
palladium which are applied on an inert support material (substrate) either
chemically or mechanically. The support consists of alumina in the form of
pellets or a honeycomb mononithic structure. Almost all monoliths being
considered are composed of material such that the noble metal will not adhere.
Thus, it must be coated (washed) with Al_0_. The catalyst coated substrate
is then canned in a stainless steel casing and placed in the exhaust system
so that the exhaust flow is directed through the catalyst bed.
As of now there is no single producer of a complete catalytic
converter package. At most there exist a few firms which will make their own
substrate and plate it with the necessary noble or base metal catalyst but
B-4
-------
even these firms will not produce canisters or can the product. Thus, in
estimating the lead time and cost to the auto manufacturer and consumer each
component of the converter must be considered separately.
Generally the substrate is produced by one manufacturer; it is then
passed onto a catalyst manufacturer who plates the substrate who in turn passes
the finished catalyst to the auto company. Some auto firms are planning to do
their own cannister production while others are seeking cannister producers.
Before considering the cost of the catalytic material and its
applications the type of substrate to be used must first be resolved.
Basically the substrate considered is of two types, pellet or beads and
monolithic. Each have different characteristics as to cost, performance,
durability and replacement.
Pellets, in general, are considerably cheaper and replacement is
a much simpler process. The raw material for alumina pellet support is very
plentiful. Reynolds has stated that they alone could supply the entire
automotive industry with alumina support for 20 years without a dent in their
reserves. Their current production is several hundred thousand tons per year
with present facilities. However, in order to supply the auto industries
Reynolds says that additional production facilities would have to be
constructed, and that such an undertaking would require at least a 3 year
committment to purchase from auto manufacturers.
The plant, which solely produces alumina support, would require a
total lead time of about 18 months before full production is under way with
preliminary engineering and construction taking 3 and 12 months respectively.
Approximately 3 additional months would be needed for plant start-up and
check out. With such a plant operating at full capacity they could supply
14 mil pounds per year at a cost of $0.41/lb. F.O.B. This will supply
enough support material for about 2,000,000 converters based on an estimate of
5-6 Ibs. per converter. Capital investment would run $4-5 million.
B-5
-------
Kaiser Chemicals is also considering productions of alumina
pellet substrate, however not much information is available. They have spent
over $1 million of their own money without getting any contracts to supply.
Should an agreement be made with any auto or catalyst manufacturer, a new plant
would be required. It would take approximately 24 months to get full
production out of the plant. Twenty-one months will be needed for engineering,
design and construction and an additional 3 months start-up.
Monoliths considered fall into two basic designs, round and oval.
All but one auto firm prefer round which has been quoted as being cheaper by
a factor of up to 2.
Some producers namely American Lava Company, hereafter called
Alco, and Corning Class have spent considerable time and money developing
monolithic substrates for converters.
Alco, a subsidiary company of 3M, has contacted all domestic auto
manufacturing and catalyst suppliers but as yet (9/1/72) has not made any
contractual agreement to supply catalytic substrate. They have made an
agreement with Ford in June '72 for the scale up of production facilities to
meet a portion of Ford's substrate requirements for 1975 model vehicles.
This agreement guarantees that if Ford should cancel their order they would
reimburse Alco for all non-recoverable expenditures.
Alco's production capabilities are in discrete production units
called "modules" with each module having the capacity to produce 1.5 million
units per year under a normal 2 shift, 5 day week basis. This could be
increased to 2.25 million units using 3 shifts. Two such units are presently
covered by a contract with Ford. The first, started in Jan. '72 is still
under construction and due to be completed in the first quarter of '73. The
second is in the planning stage and will not be completed until the 1st
quarter of '74. These two modules alone could supply all of Ford's needs for
1975. Additional modules would be required to supply other auto manufacturers.
B-6
-------
With their present Chattanooga plant, Alco would set up 4 such
modules with a capacity of 6-9 million units and only a warehouse would be
needed for raw material storage. This is the only critical lead time item
mentioned. Construction must be started by 10/72 to meet their planned
schedule of completion in Sept. '73. Should demand increase, additional
modules could be installed in other 3M plants located outside Chattanooga.
According to Alco's Manufacturing Scale-up for Substrates, they
could reach a production level of 4.5 million units a year by July '73, only
18 months after program initiation of Jan. '72. Thus, Ford's requirements of
3 million units a year could be met in considerably less time than the present
agreement schedule provides. Twenty-six months is the indicated requirement
for the Alco goal of 9 million units by March, 1974. Alco claims that
March '73 was the latest they could accept on order from General Motors to
build substrate in quantity. This suggests that Alco could double the number
of Modules from 2 to 4 in a matter of 12 months. They also claim that by
March '75 production could reach 30 million units a year and no new construction
of a plant would be needed. Should orders exceed this amount, new facilities
would then be needed.
Basic component values were quoted at $5 for the ceramic substrate
and $8 for the platinum. However, Matthey-Bishop, a catalyst manufacturer,
has received cost quotes from Alco of $2.81 per round substrates and almost
double for oval configurations. It is Alco's estimate that a complete
monolithic converter should cost no more than $40-$50 for light duty vehicles.
Corning Glass is considering supplying only monolith substrate.
As yet they have not made any contractual committments with catalyst platers
or auto manufacturers. They are currently operating a pilot production
facility with a monthly output of 1500-3000 units. With added equipment,
they expect a production capacity of 30,000 or more per month by June '73.
There seems to be no lead time problem with vendor-parts. Also, raw materials
are available at any time in carload lots. Cost for round configurations is
estimated to be $2.54 per unit and slightly higher for oval.
B-7
-------
A number of catalyst manufacturers have already been contacted by
auto firms. Monsanto has originally only considered a pellet type base metal
catalyst but has since then been encouraged to use noble metal as well. They
have no plans to manufacture substrate or canisters. The substrate would be
purchased from Kaiser and/or Reynolds and canister production would be handled
by auto manufacturers themselves. They foresee no difficulties in acquiring
noble metal. Monsanto has established good relations with Russia and has
already requested permission from the State Department to investigate a noble
metal deal with them.
Monsanto has no existing facilities that could be modified for
catalyst production. Thus, construction of a new plant would be needed but a
firm commitment to purchase would be required before any detail design and
construction is started. The anticipated production would be 10-50 mil
pounds of plated substrate per year enough for 2-10 mil converters.
Since this would be a major undertaking for Monsanto the total
estimated expenditure is of the order of several million dollars. They have
indicated that a lead time of 24 months from the date of site selection until
full production is under way. Site evaluation, design and construction would
take 21 months with an additional 3 months needed for plant checkout and
start-up. This lead time schedule is in reasonable agreement with Reynolds
and Kaiser. Also, it is compatible with the 18 month lead time required of
their noble metal supplies. No schedules compression has been considered as
yet.
Even though most catalyst manufacturers could produce both Pellet
and Monolith type converters, pellet catalyst are favored by some primarily
because of their lower cost, durability and the low cost of replacement which
would run between $20-$30. For example, Oxy-Catalyst maintains that they
would need 0.03 to 0.04 troy ounce of platinum per converter with the pellet
type costing approximately $10 whereas their monolith would run anywhere from
$40-$50.
B-8
-------
Oxy-Catalyst, like other catalyst manufacturers, would require a
commitment from auto firms before any new facilities are built. Their schedule
lead time for a new plant is 20 months. Sixteen months would be needed for
design, engineering and construction; another 4 months for plant shakedown.
This schedule is applicable to both pellet and monolith type catalysts and is
based on a start date of Sept. 1, 1972; however, a decision with respect to
catalyst type must be made by Dec. 1972. Thus, completion would be around
May 197-1 with a capacity of 15-20 million pounds of Pellet-type catalyst.
They could compress their schedule by 3 months with a cost increase of up to
10 percent. If monoliths are the choice, Alco and/or Corning would probably
be the supplier with a delivery date of March 1974. Thus, storage would be
necessary for a couple of months. However, pellet suppliers lead time would
correlate very well.
Though pellets are cheaper, they do not perform as well as
monoliths. Matthey-Biship is considering supplying plated monolith-type
converters at an estimated cost of $15-$18. This includes the substrate,
Al-O, wash coat as well as a noble metal coating (0.04 ounce of platinum and
a proprietary amount of other non-noble metals). They do not intend to
package the converter, but are willing to give aid, without cost, to the
canister manufacturer. It has been estimated by Matthcy-Bishop that packaging
may run from $0.50 to $0.60 per unit.
Should Matthey-Bishop get a contract to produce a catalyst, they
would need to build a new facility. The lead time would be about 21 months;
design and contracting should take 3 months. Construction and installation of
equipment is estimated to take 14 months; the remaining 4 months is needed for
start-up and shakedown. The new facility would have an output of 1.8 mil.
units a year and cost around $4 million.
Since plant expansion is rather simple, capacity could be further
increased, however, notification must be received by April 1973. Orders for
substrate would have to be placed before this date. Their lead time correlates
very well with American Lava, a potential substrates supplier.
B-9
-------
Several catalyst manufacturers are considering producing their
own substrate. Universal Oil Product and W. R. Grace Co. are both considering
producing pellet substrate and then adding their catalytic material. Grace
has the capacity with slight modification to existing equipment to produce
15-20 mil. pounds of pellet substrate a year. Since this would not be enough
to supply any one auto firm, they would have to contact outside pellet suppliers.
Grace has already made plans to produce a monolith but as yet has
not made any contractual agreements with the auto firms. They may make some
agreement with outside monolith suppliers if their monoliths are not accepted.
Following the receipt of a contract or purchase order, Grace
would build either a pellet of monolith catalyst plant at a cost of $5-15
million. The scheduled lead time given for the plants are 24 mos. for pellet
and 22 mos. for monolith. Engineering and design would cover 3 mos.
Construction of the pellet plant is estimated to take 18 months whereas the
monolith would take 16 months. The remaining 3 mos. would involve plant
shakedown and checkout.
No scheduled compression is possible for their monolith plant;
however, the pellet catalyst lead time could be compressed by 3-6 months at
a $0.10 - 0.05 per pound cost increase.
Universal Oil Products is considering an output of 5 million units
a year regardless of which catalyst is chosen. They prefer a monolith and
could supply it at a cost of $10-12. Nexv facilities have already been
planned; however, a final decision by G. M. on whether to order pellet or
monolith is being awaited before construction beings. There is an estimate
of 20 months before shipment could commence which would be around June 1974.
B-10
-------
REFERENCES
1. Trip Report - Reynolds Metals Company, Production Lead-Time Study, from
M. G. Hinton/W. U. Roessler, Aerospace Corp., 30 August 1972.
2. Trip Report - Kaiser Chemicals, Production Lead-Time Study, from
0. Hamberg, Aerospace Corp., 27 September 1972.
3. Trip Report - American Lava Corporation, Production Lead-Time Study,
from F. P. Hutchins, EPA, 1 September 1972.
4. Trip Report Corning Glass Works, Production Lead-Time Study, from
L. Forrest/W. Smalley, Aerospace Corp., 11 September 1972.
5. Trip Report - Monsanto Company, Production Lead-Time Study, from
W. U. Roessler, Aerospace Corp., 15 September 1972.
6. Trip Report - Oxy-Catalyst, Inc. Production Lead-Time Study, from
W. U. Roessler/M, G. Hinton, Aerospace Corp., 6 September 1972.
7. Trip Report - Matthey-Bishop, Production Lead-Time Study, from
W. U. Roessler, Aerospace Corp., 16 October 1972.
8. Trip Report - W. R. Grace Company, Production Lead-Time Study, from
M. G. Hinton/W. U. Roessler, Aerospace Corp., 31 August 1972.
9. Trip Report - Universal Oil Products, Production Lead-Time Study,
30 August 1972.
10. Aerospace Report No. ATR-73-7322)-!; 28 July 1972.
B-ll
------- |