EPA-AA-EOD-80-1
         Correlation  Report



         1979 EPA-Volkswagen

 Light Duty Diesel Correlation Study
                 by

            Carl Scarbro
          Correlation Group
       Testing Programs Branch
   Engineering Operation  Division
Office of Mobile Source air Pollution
      Ann Arbor, Michigan  48105

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 Introduction

 In  response  to a meeting with representatives of  Volkswagen  on  September  14,  1979,
 a  correlation  study  was organized  to  characterize  some  of the  factors  causing
 hydrocarbon offsets during  the 1980  diesel certification  program.   (Volkswagen read
 40% lower hydrocarbon emissions than EPA)   The hypotheses presented at this  time  by
 Volkswagen were:   (1) offsets do  not  occur because of sample line variations from
 lab to lab,  and  (2)  offsets are caused  by  diesel  fuel  composition  differences
 between  EPA's  fuel  and  Volkswagen-Wolfsburg's  fuel.   These two  hypotheses  were
 tested in two separate experiments at EPA as part of the correlation study.

 After  completing the  testing for the  above two  studies,  Volkswagen returned the
 test vehicle  to their Wolfsburg  facility  in Germany  and performed an  independent
 study with larger  vehicle cooling  fans.  VW also began a  second, but  similar,  vehi-
 cle in an  interlaboratory  round  robin with the  first  vehicle.   The purpose of the
 fourth study  using the two  vehicles  was to identify test cell  environment  effects
 on  vehicle warmup during testing.

 In  November Volkswagen brought both vehicles to  the United  States and requested EPA
 to  do a series  of  six Hot  LA-4s on each vehicle  at the EPA facility.   We agreed  to
 do  the test  cell environment effects  study if they would  test  the vehicles  in  as
 many non-Volkswagen laboratories  as they  could.   They accepted.  These tests  were
 performed on  Volkswagen's test fuel  used in this  country and performed  in an  iden-
 tical manner at the six facilities participating  in the round  robin.

 This report is  the summary  of the three different studies performed  in  cooperation
 with EPA plus the results  of the independent Volkswagen  cooling fan experiments.
 These  studies  included  similar  vehicles  and facilities,  but  addressed  different
 correlation cause/effect relationships.


 Conclusions

 Factors which  can  cause  a hydrocarbon offset  between  EPA  and  VW's   development
 facility in  Wolfsburg have  been   indentified  as  cooling  fan capacity,  test  cell
 environment's  effect  on vehicle  and/or sample  system temperature stabilization,
and possibly an effect due to fuel characteristics  and/or  a  fuel  change effect.

 The  offsets   between  Volkswagen-Wolfsburg, Chrysler  Proving  Grounds,  and  EPA-Ann
 Arbor on a large number of  LA-4s on  two Rabbit diesels is below 6%.  VW-Toledo and
 VW-Westmoreland are 25% below EPA  and FIAT  is 50%. lower.


Recommendations

 It  is unfortunate that a better real world simulation  of  air  movement over the test
vehicle is not readily adaptable  to present certification testing, but the use of a
standardized single speed fan would facilitate more comparable results between test
 facilities.   It  is also desirable that  test personnel have  adequate direction to
 duplicate the  fan  to  vehicle placement  that is desired by the manufacturer, within
 the constraints of the Federal Register.

 The soak control vs.  oil temperature controlled vehicle  tests  indicate cell  envi-
ronment does effect the vehicle and/or sampling system  thermal state before startup.

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Since  test  cells  are  not easily  redesigned  to  reflect  one another  one  must
therefore perform hot temperature stabilized LA-4s vs. hot  soak controlled LA-4s to
quantify offsets due to the cell environment.

The fuel controversy is best resolved by a standard test  fuel that  can be bought by
all manufacturers from a single lot.
Vehicles and Test Plans

The  chronology of  events, test  plans, test  fuels, and  locations are  summarized
below:

                                                                       Sample Line
               Test Site     Vehicle     Fuel    n/Vehicle      Fan    Temp. °F
Location       	

VW-Toledo         1
VW-Westmoreland   2
EPA-Ann Arbor     6
EPA-Ann Arbor     6
VW-Toledo         1
EPA-Ann Arbor     6
EPA-Ann Arbor     6
EPA-Ann Arbor     6
EPA-Ann Arbor     6
VW-Toledo         1
                                1
                                1
                                1
                                1
                                1
                                1
                                1
                                1
                                1
                                1
       AMOCO-50
       AMOCO-50
       AMOCO-50
       AMOCO-50
       AMOCO-50
       AMOCO-50
       Wolfsburg
       EPA
       AMOCO-50
       AMOCO-50
Vehicle was shipped to Wolfsburg, Germany.
VW-Wolfsburg
VW-Wolfsburg
VW-Wolfsburg

VW-Wolfsburg

VW-Wolfsburg
VW-Wolfsburg
                  6
                  6
                  Inspection
                  4,6,8
                  Inspection
                 .4,6,8
                  6
                  6
1
1
1
2
2
AMOCO-50
AMOCO-50
AMOCO-50

AMOCO-50

AMOCO-50
AMOCO-50
Vehicles were shipped to the United States.
VW-Westmoreland   2
VW-Toledo         1
VW-Toledo         1
FIAT-Dearborn     1
Chrysler          5
EPA-Ann Arbor     6
                                1&2
                                1
                                1&2
                                1&2
                                1&2
                                1&2
       AMOCO-50
       AMOCO-50
       AMOCO-50
       AMOCO-50
       AMOCO-50
       AMOCO-50
               6
               6
               6
               6
               6
               6
               6
               6
               6
               6
11
18
40

34

6
6
              6
              6
              6
              6
              6
              6
         5000
         5000
         5000
         5000
         5000
         5000
         5000
         5000
         5000
         5000
     SCFM
     SCFM
     SCFM
     SCFM
     SCFM
     SCFM
     SCFM
     SCFM
     SCFM
     SCFM
5000 SCFM
5000 SCFM
5000 SCFM
5000 SCFM
5000 SCFM
         5000 SCFM
         5000 SCFM
         5000 SCFM
         5000 SCFM
         5000 SCFM
         5000 SCFM
375
375
375
322
375
375
375
375
375
375
375
375
375
                              5000 SCFM   375
375
375
            375
            375
            375
            375
            375
            375
All test sequences were 6 Hot LA-4s or 1 FTP and 5 Hot  LA-4s  to maximize the amount
of data that  could be collected in the allotted test time and equipment availabil-
ity.  The specifics on vehicle preps and mileage accumulation for the three studies
are outlined in Tables 1, 3, and 5 in the appendix.

Vehicle *1  was a 1978 production  VW  diesel Rabbit  and is referred to  as  the  soak
controlled  vehicle in  the test  cell environment  study.  Vehicle  #2  was  another

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1978  production VW  diesel  Rabbit but  with temperature monitoring  of engine oil,
engine  intake  air,  and fuel  in  the  fuel tank  .   This #2 vehicle was the tempera-
ture controlled vehicle which, after  the 10 minute soak, was driven at 30 mph until
the  engine oil temperature was  200°F.   The vehicle then returned  to idle and the
hot LA-4 began.

Discussion of Results

Test results are presented in the appendix  for  each  specific vehicle/test procedure
combinations.

Volkswagen's claim of hydrocarbon measurement insensitivity to sample line tempera-
ture on the Rabbit diesel was validated at EPA.   It  is interesting  to note that
most diesel vehicles including the VW powered Volvo  and  VW built Audi 5000 are sen-
sitive  to  sample system  temperature  in the continuous  diesel hydrocarbon system.
This has been  verified  by EPA-Ann Arbor, VW-Wolfsburg, and Volvo-Goteborg.  Figure
1 in the appendix demonstrates it is characteristic  for  diesel hydrocarbon measure-
ments to  be sensitive  to temperatures, but this  sensitivity  was not observed for
the VW Rabbit that was tested at  EPA.

Volkswagen's hypothesis that different  fuels cause offsets on hydrocarbon emissions
was not proved  or  disproved  in our test procedure.  Statistically  there are emis-
sion  offsets  for  both HC  and  C02  between EPA's  diesel #2  and  Wolfsburg  fuel,
AMOCO-50 and  Wolfsburg  fuel, but not  between  AMOCO-50  and EPA's diesel #2.   When
viewing data chronologically, however,  the  total  variability  of the vehicle ranged
from  .55gram/mile  to a low of .34 gram/mile on the baseline fuel.  This contained
the  sample means of the other  test  fuels.   Experience with  Volvo certification
vehicles:.using  Volkswagen technology indicates  that  something  during a fuel switch
may cause  a  large  hydrocarbon offset  that becomes smaller as  the vehicle accummu-
lates mileage.   This report therefore  does  not  resolve  the fuel  switch contro-
versy.  (See Fig. 2,  3,  4 for chronological  test data.)

The analysis of the  fuels used in the study are shown  in the appendix.  The differ-
ences in Volkswagen's and EPA's  analysis were  dramatic.   Using EPA's analysis, the
AMOCO-50 was within Federal Register specifications, except for the initial boiling
point and  10% point in  the distillation.  The Wolfsburg  fuel was out of specifica-
tion  for  aromatics,  API  Gravity,  viscosity,  flash  point,  initial  boiling point,
10%, and 50% in the distillation.

Hypothesis testing (T-stat) accepted the hypothesis  that the cold start hydrocarbon
data mean .was  equivalent  to  the  hot  start data, on  all  three  fuels overall during
the fuel switch test procedure.

The result of the two  vehicle test procedures,  soak  time vs.  soak  time  plus oil
temperature stabilization, did indicate the degree  of offset  between EPA  and the
other labs due to cell environment differences.   The  vehicle  that was temperature
stabilized had  approximately the same  test to test variability as the  soak time
stabilized vehicle,  but had a lower  lab to lab  offset  for  hydrocarbon emissions,
indicating ambient cooling conditions during phase 1 and the  10  minute soak causes
some of the offset found between  manufacturers and EPA.

Variability over time can be seen in Figure 4,  5,  6, and 7  for both test vehicles.
The soak  controlled test vehicle  displays more  variability in  hydrocarbon  emis-
sions,  even  site to  site within Volkswagen-Wolf sburg,  than the  temperature con-
trolled vehicle.   Whether the  temperature of  importance is  vehicle intake air,

-------
engine oil  or sample  exhaust  system through  to  the continuous hydrocarbon  sample
point was not determined by this study.

Volkswagen performed tests on both vehicles using a  different  capacity  cooling  fan,
both  in   Germany  and  Toledo on  vehicle  #1  and  in Germany  only  for vehicle #2
using the vehicle handling procedure outlined  in  Table  5.  The larger  cooling  fans
caused an approximate  20%  increase  in HC.  The small capacity fans  were the  origi-
nal cooling  fans  used  in  Wolfsburg for  Volkswagens certification  work.   At  that
time Volkswagen was 40% lower  than  EPA in diesel hydrocarbon results  in the  FTP.
The  critical temperature  in this  study,  as  measured  by vehicle  #2 temperature
recorder, was engine intake  air.   The cooler the intake  air  the  higher the  hydro-
carbon emissions.   (See Figure 8 and 9).

The tests conducted by Fiat  in  Dearborn and Volkswagen Toledo indicated the  impor-
tance of cooling fan location.   LA-4s 1 to 3 in the  Fiat tests had a different fan
location than Run's  4  to 6  (see  Figure 10) on the temperature controlled vehicle.
The  lower  temperature  traces   for  Run's  4  to 6  resulted in  slightly  higher HC
results.   Toledo tests for the same vehicle was  an  attempt to better  simulate air
intake temperature  traces generated  at  EPA.   The  result of  the  experiment  did
bringToledo's HC emissions closer to the level of hydrocarbon emissions measured at
EPA on the same vehicle over  the same test procedure.  (Figure 11 and 12)

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                            APPENDIX
Table 1

Table 2


Table 3

Table A


Table 5


Table 6

Table 7


Table 8


Table 9


Table 101"


Table 11

Figure 1


Figure 2


Figure 3


Figure A

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10
Vehicle Test Plan for Volkswagen HFID Sample System Temperature Study.

HFID  Sample System  Temperature Study  Gaseous  Emissions from  VW Rabbit
*1 for Hot Start LA-4s.

Vehicle Test Plan for Volkswagen Fuel Effects Study:  EPA Tests.

Hot  LA-A Emission  Results  for Volkswagen  Fuel  Effects Study:   Three
Fuels, Vehicle #1, Sample Line Temp, at 375°F, EPA Tests.

Vehicle Test Plan  for  Volkswagen Test Cell Effects Study at Six Facili-
ties.

Vehicle Coast Down Times (In Seconds)

Gaseous  Emission  from Vehicle  *2,  Temperature  Controled  Vehicle,  at
Six Facilities for Volkswagen Test Cell Effects Study.

Gaseous  Emission  from  Vehicle  #1,  Soak  Controled  Vehicle,  at  Six
Facilities for Volkswagen Test Cell Effects Study.

Offset  on  Two Volkswagen  Rabbits  at  Five Facilities for  Hot  Start
LA-As:  Fuel AMOCO 50.

Cooling  Fan Capacity  Study  on  VW  Rabbits #1  and #2:   Fuel  AMOCO  50,
Sample Lines at 375°F.

Analysis of Diesel Test Fuels.

Hydrocarbon Response vs.  Sample System Temperature for  Vehicles Driving
Hot Start LA-As.
HC  and  NOX vs.  Test  Sets  in  Chronological  Order  on Vehicle
September 1979.
                                                                       in
CO  and  C02 vs.  Test  Sets  in  Chronological  Order  or Vehicle  #1  on
September 1979.

Hydrocarbon vs. Time:  Vehicles #1 and #2.

CO vs. Time:  Vehicles *1 and #2.

NOX vs. Time:  Vehicles #1 and #2.

C02 vs. Time:  Vehicles #1 and #2.

Site 6 VW Wolfsburg, Hot LA-As, Fan-cap. < 5000 cfm.

Site 6 VW Wolfsburg, Hot LA-As, Fan-cap. 5000 cfm.

Fiat-Dearborn,  Hot LA-As, Two Fan Locations.

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Figure 11  VW-Mobile Lab Toledo, Fan Location #1 for Six LA-4s.
Figure 12  VW-Mobile Lab Toledo, Fan Location #2 for Six LA-4s.
Calculations

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             Table 1    Vehicle Test Plan  for Volkswagen
                HFID  Sample  System Temperature Study

            Vehicle *1   Fuel Used:  AMOCO 50   EPA Tests
Procedure
LA-4 prep, no fuel drain, 12 hr. soak
FTP + 10 min. soak
LA-4 + 10 min. soak
LA-4 + 10 min. soak
LA-4 + 10 min. soak
LA-4 + 10 min. soak
LA-4 + 10 min. soak
LA-4 prep, no fuel drain, 12 hr. soak
FTP + 10 min. soak
LA-4 + 10 min. soak
       10 min. soak
LA-4
LA-4
LA-4
LA-4
     + 10 min. soak
     + 10 min. soak
     + 10 min. soak
                                          Sample System Temp in °F
375°F
375°F
322°F
322°F
322°F
375°F

375°F
375°F
322°F
322°F
322°F
375°F
                Table 2  HFID Sample System Temperature Study
           Gaseous Emissions from VW Rabbit #1 for Hot Start LA-4s
Facility
EPA-
Ann Arbor
n=5
EPA-
Ann Arbor
n=4
HC
Statistic g/mile
!<
S
%c.v.
><
s
%c.v.
.50
.02
4
.49
.04
8
CO
g/mile
.98
.02
2
.98
.05
5
NOX
g/mile
.96
.02
2
.94
.02
2
C02 Sample
g/mile Fuel Filter Temp.
232.4 AMOCO-50
1.3
1
231. AMOCO-50
1.4
1
375°F


322°F



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                      Table 3   Vehicle Test Plan for Volkswagen
                            Fuel Effects Study:  EPA Tests
                            Vehicle #1  Sample Line 375°F
Procedure
LA-4 prep
FTP, 5 Hot LA-4s, 10-12 min. soaks between tests
Fuel drained and filled to 50%
40 road miles and LA-A prep, 12 hr. soak
FTP, 5 Hot LA-As, 10-12 min. between tests
Fuel drained and filled 50%
AO road miles and LA-A prep, 12 hr. soak
FTP, 5 Hot LA-As, 10-12 min. between tests
Fuel drained and filled 50%
AO road miles and LA-A prep, 12 hr. soak
FTP, 5 not LA-A's, 10-12 min. between tests
Fuel

AMOCO 50
AMOCO 50
Wolfsburg fuel
Wolfsburg fuel
Wolfsburg fuel
EPA's diesel #2
EPA's diesel #2
EPA's diesel #2
AMOCO 50
AMOCO 50
AMOCO 50
        Table A  Hot LA-A Emission Results for Volkswagen Fuel Effects Study:
               Three  Fuels, Vehicle #1, Sample Line at 375°F, EPA Tests

Facility

EPA
Ann Arbor"'
n=A
FTP
EPA
Ann Arbor
n=5
FTP
EPA
Ann Arbor
n=6
FTP
EPA
Ann Arbor
n=6
FTP
EPA*
Ann Arbor
n=21

FTP
Test
Date

Sept. 25,
1979 "

(n=l)
Sept. 27,
1979

(n=l)
Sept. 29,
1979

(n=l)
Sept. 28,
1979

(n=l)
Sept
1979


(n=4)

Statistic

f
s
°/r \t
/OO. V .

>r
s
%c.v.

7
s
%c.v.

>r
s
%c.v.

—
s
%c.v.


HC
g/mile

.AO
.01
2.5
.A3
.36
.OA
11
.32
.A5
.02
A
.AA
.A3
.05
12
.Al
.41
.05
12

.40
CO
g/mile

.95
.01
1
1.0
.94
.06
6
.90
.93
.05
5
.90
.94
.05
5
1.0
.94
.03
3

.952
NOX
g/mile

.96
.01
1
.98
.94
.02
2
.94
.91
.03
3
.93
.93
.02
2
.96
.93
.03
3

.95
C02
g/mile

234.0
1.5
1
239
221.0
1.6
2
224
224.6
2.2
1.0
229
226.0
2.2
1
235
226.1
5.2
2

231.75

Fuel


AMOCO-50


Wolfsburg



EPA's
#2 diesel


AMOCO-50


%
AMOCO
Wolfsburg
EPA's #2
diesel

*The mean and standard deviation of all tests  in the fuel  effect  study at EPA on
 Vehicle #1

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                 Table 5  Vehicle Test Plan for Volkswagen
                 Test Cell Effects Study at Six Facilities

              Fuel  used:   Toledo AMOCO   Sample lines at 375°F


Testing Sequence       Vehicle  2                       Vehicle  1

       1           LA-4 prep                        LA-4 prep
       2           12-hour soak                     12-hour soak
       3           FTP                              FTP
       4           10-min. soak+                    10-min. soak
       5           30mph until oil temp=100 C
                    stop vehicle
       6           Hot LA-4                         Hot LA-4
       7           Repeat sequence 4 thru 6         Repeat sequence 4 thru
                    until 5 Hot LA-4's are          6 until 5 Hot LA-4's
                    completed                       are completed
       8*          (3) 55 to 45mph coast downs      (3) 55 to 45mph coast
                                                    downs


       *At EPA and VW-Westmoreland only.


                   Table  6  Vehicle  Coast  Down Times  (In Seconds)

                          Vehicle #1                      Vehicle *2
   Facility       Date      5>5-5mptv     5£-45mph   Date      55-5roph    55-45mph


VW-Westmoreland   9/79       96           11.6     12/79      91           12.1

VW-Toledo         9/79       82           10.2

EPA-Ann Arbor     9/79       95           11.3     12/79      —           11.1

EPA-Ann Arbor     1/80       —           11.2

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Table 7  Gaseous Emissions from Vehicle #2 Temperature Controlled Vehicle
         At  Six  Facilities  for  Volkswagen  Test Cell  Effects  Study

Facility

VW-
Wolfsburg
Cells 4,6,
8, Inspection
n=34
VW-
Westmoreland
n=14
VW-
Toledo
n=18
FIAT
Ann Arbor
n=6 •---
Chrysler

n=6
EPA
Ann Arbor
n=6
Test
Date

Nov
1979



Dec
1979

Nov-Dec
1979

Dec
1979

Dec
1979

Dec
1979


Statistic

~x
s
SflC.V.


~x
s
%C.V.
x"
s
%c.v.
><
s
%c.v.
a
s
%c.v.
><
s
%c.v.
HC
g/mile

.30
.045
15


.27
.03
11
.30
.04
13
.23
.02
9
.30
.03
10
.30
.02
7
CO
g/mile

.85
.085
10


.85
.05
6
.98
.07
7
.87
.03
3
.94
.04
4
.801
.036
4
NOX
g/mile

.90
.08
8


.93
.04
4
.92
.025
3
1.03
.09
9
1.04
.035
3
.996
.012
1
C02
g/mile.

244.8
7.3
3


239.5
3.5
1
247.8
3.3
1
255.6
9.8
4
247.4
2.15
1
237.4
3.3
1

Fuel

Toledo
AMOCO



Toledo
AMOCO

Toledo
AMOCO

Toledo
AMOCO

Toledo
AMOCO

Toledo
AMOCO


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Table 8 Gaseous Emissions from Vehicle ffl Soak Controlled Vehicle
At Six Facilities for Volkswagen Test Cell Effects Study

Facility

VW-
Wolfsburg
Cells 4,6,
8, Inspection
n=30
VW-
Westmoreland
PA
n=6
VW-
Toledo
n=6
FTP
-j"
FIAT

n=6
Chrysler

n=6
EPA
Ann Arbor
n=6
FTP
Test
Date

Nov
1979



Nov-Dec
1979


Nov-Dec
1979

(n=l)

Dec
1979

Dec
1979

Oan
1979

(n=l)

Statistic

7
s
%c.v.


7
s
%c.v.

>r
s
%C.V.


X
s
%C.V.
x"
s
%C.V.
>T
s
%C.V.

HC
g/mile

.40
.08
20


.30
.018
6

.30
.005
2
6
.35
.20
.02
10
.41
.015
4
.39
.04
10
.35
CO
g/mile

.99
.16
16


.96
.035
4

.93
.067
7

1.0
.87
.03
3
1.01
.025
2
.96
.03
3
1.0
NOX
g/mile

.92
.08
9


.97
.05
5

.91
.03
3

1.09
1.00
.03
3
.966
.015
2
1.06
.02
2
1.09
C02
g/mile

247.1
19.8
8


239.7
2.5
1

242.2
5.26
2

246
247.8
3.1
1
234.0
1.7
7
232.9
3.4
1
246

Fuel

Toledo
AMOCO



Toledo
AMOCO


Toledo
AMOCO



Toledo
AMOCO

Toledo
AMOCO

Toledo
AMOCO



-------
 Table 9   Offset1 on Two Volkswagen Rabbits
     at Five Facilities for Hot Start LA-4's: Fuel AMOCO-50
     Sample Lines at 375°F
Offsets on
Vehicle #1
6 tests at EPA
HC'
CO
NOX
C02
Offsets on
Vehicle #2
6 Tests at EPA
HC
CO
NOX
C02
!% offset = (Facility
VW-
Wolfsburg
n=30
2.6%
3.1%
-13.2%
6.1%
n,34
0.0%
6.1%
-9.6%
3.1%
- EPA) * 100
VW-
Toledo
n=21
-23%
-3.1%
14.2%
4.0%
n=18
0.0%
22.3%
-7.6%
4.4%

VW-
Westmoreland
n=6
-23%
0%
-8.4%
2.9%
n=!4
-10.0%
6.1%
- 6.6%
0.9%

Fiat
n=6
-48.7%
- 9.4%
5.6%
6.4%
n=6
-23.0%
8.6%
3.4%
7.7%

Chrysler
n=6
5.1%
5.2%
-8.9%
4.7%
n=6
0.0%
17.4%
4.4%
4.2%

EPA

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Facility
                  Table 10  Cooling Fan Capacity Study  on VW  Rabbits
                   *1 and #2: Fuel AMOCO-50, Sample Lines at 375°F
                                  HC
                      CO
NOV
Statistic   g/mile    g/mile   G/mile
C02
g/mile
Fan
Capacity
Vehicle *1
VW-
Wolfsburg
Cell #6
n=ll
VW-
Wolfsburg
Cell #6
VW-
Toledo
n=6
VW-
Toledo
1=6 -^
Vehicle *2
VW-
Wolfsburg
Cell #6
n=6
VW-
Wolfsburg
Cell #6
n=6

10-79


10-79


12-79


12-79



8-79
9-79


10-16
11-8



X
s
%C.V.

x~
s
%c.v.
x
s
%C.V.
X
s
• %C.V.

•£
s
%C.V.

7
s
%C.V.


.42
.055
13

.33
.04
12
.30
.005
2
.25
.023
9

.24
.015
6

.30
.015
5


1.03
.115
11

.92
.04
4
.93
.067
7
.93
.09
10

.82
.01
1

.82
.02
2


.88
.033
4

.89
.04
4
.91
.028
3
.97
.02
2

.83
.012
1

.90
.037
5


"239.0
8.84
4

237.3
5.9
2
242.2
5.3
2
241.5
3.6
1

243
3.2
1

241.9
3.7
2


approx.
5000cfm

Less than
5000cfm

high
capacity

low capacity
tan


Less than
5000cfm


approx .
5000cfm



-------
                               Table 11  Analysis of Diesel Test Fuels
Cetane Number

  Aromatics
  Olefins
  Saturates
Distillation
Data in °F
  IBP
    5%
   10%
   20%
   30%
   40%
   50%
   60%
   70%
   80%
   90%
   95%
   EP
               AMOCO 50
                's Analysis
                             Wolfsburg
                             diesel #1
                             Wolfsburg
                             diesel #1
 i9.2
                                                          Federal
  AMOCO 50       diesel #1      diesel #1     XEPA's     Register
EPA's Analysis1 VW's Analysis EPA's Analysiyaiesel #2 Specification^

                                               44.0
A95
43.3

29.0%
  .5%
70.5%
                                 0.0
54.5
                              368
                                                           35.6
41.2
1.87cst
118°F
.276wt%
249
345
370
391
408
430
452
475
501
530
573
607
627
98.1
lOOvp
o.o\
34.4
2.61cst
138°F
.38wt%
360

420



510



596

627



42-50

27% min.



33-37

2.0-3.2cst

130°F min.

0.2-0.5



340-400

400-460



470-540



550-610

580-660
                                                                             6.80
•'•The averageyof two samples drawn from the same fuel batch.

-------
                                               15
                              Table 11  Analysis of Diesel Test Fuels
Wolfsburg Wolfsburg Federal
AMOCO 50 AMOCO 50 diesel #1 diesel #1 EPA's Register
VW's Analysis EPA's Analysis1 VW's Analysis EPA's Analysis diesel #2 Specification;
Cetane Number
Cetane Index 48.5
Aroniatics '"-^^ •-••-• '••'•'.'••
. Olefins . '^' : " ;
Saturates
API Grav. 36.5
Vis at 40 C 2.0cst
Flash Point 153°F
Sulfur
Distillation
Data in °F
IBP 341
5%
10% 402
20%
30% -.--..
40%
50% 495
60%
70%
80%
90% 601
95%
EP 615
Recovery
Residue
Total Recovery
Loss
43.3
45.6 50.0
.•:;29.0% •••'.; jU-V;^.'- •-..•.,..-,:•• •
••- ;' -.5% :'""~;---" ' •'• '
70.5%
35.4 42.34
2.21cst 1.7cst
131°F 137°F
.271wt%


276 318
379
396 368
425
446
467
486 455
506
526
548
580 582
610
626 623
98.3
1.7
100.0
0.0
48.2 44.0
50.0 47,4
20.0% 35.6
.5%
79.5%
41.2 34.4
1.87cst 2.61cst
118°F 138°F
.276wt% '.38wt%


249 360
345
370 420
391
408
430
452 510
475
501
530
573 596
607
627 627
98.1
1.9
100.0
0.0
42-50 .

27% min.


33-37
2.0-3. 2csi
130°F min
0.2-0.5


340-400

400-460



470-540



550-610

580T660




C/H Ratio
6.80
-'•The average of two samples drawn from the same fuel batch.

-------
 i
<;

-------
                                                                   ---T--:-:--:  -i -t

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                          t-._ufl Krv'HieWt?	L^_rToVeAc> 4..*v tnocci. JIEl

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 -iTbS-isM-—-
ijipzi^izn.
 •n~~v>-'

 (:QO   y^-
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                                                                       1 ! _l_^J_:_:
                                                                      -U—jJ-:-L
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                                                                                          rr


 :	   ^

feS>::
l.*^'-
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-------
                                 -, ___,_,_	rr—.,_._        ._^_rr^_1 ^  .         I     '    /     ~-^~-r~J~-


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                                                                                         	. ___ •    _	_j_. _, i. _L_.,__	j	i



-------
j un: mot fiNv 11101 im
 HDMI i 01 o; >: M -IWMJ

-------
KDV AMMV.1S'>-',1.| »ui I1IO.'. MNV II10I 'li
                    '  M.'illl  I l»l Oi X 0'.  IW-

-------
mn Hint am HIOI 'HI:
II3NI I Ol 05 X Ol-IW-U(

-------
s =

-------
Test #
?/J2^^
1U^5"
HUl-
HUZ
It WO
UMI _




Date
S~£3
J-^3
S-^9
S-A9
7-6
?-.«
X
• s
2S
t'S
*?
HC (g/mi)
0-2S
0' M .
0- AS
O- £ ( '"
0- £2, -
V- A3-
0>JH
0. 0 i$
0.03
o.o&
CO" (g/ml)
0'?£
0.S&.
0- Sf
0*3 I
0-83
0.30
0-2Z
0- 0 I
O.Q3L
0-0 (
NOX (g/mi)
O.^^i
o.w
0.8S
OJX \
o.SZ- -
0.-i3
' o. 92,
Q.oOL
G.02
(9-0 /
C02 (g/mi)
£42.6
W3..8
JWrt
XHS.I
A HO. 6
2 16. 3
<2H3
1.?.
6.1
J. £ ' • !

-------
J.
Test §
72 Jtff
IbHbl
IZWS
13031
1303J
nom



•
Date
]0-l(,
10- ft
to-30
If- 1
.11-4
l(- 12
X
s
^3
^ -f
T^"
IIC (y/mi)
^.j; .
^•J2
9.3.8

JW6.S
<2<13.3
ZHIA-
3.70
l.H
3.7

-------
Fv«v,  tO
I/Ill/
                 Hot
Test *
/
^
J .
^
5
(,




Date
UL'-3
IS.- 3
12-3
IS.- 3
tt-3
«*3
X
3
2s
*•-$
VTTI
HC (g/rr.i)
^-,23 - -•
l?-^/
G.ZJ:"
0.
3.63
/?-3
' 9.< '

-------
: 1113354(13
Test 1
1
*
3 •
Y
5




*
Date
IhW
//-In
11-30
If -30
11*30

X
3
Is
t -5
"j/rft"
HC (g/mi)
^?.52^ - -
'0-2*
0.21
o-
-------
         \fW -
Test §
      a-
       •I
      ii-
      12-1  JJ
      a- 1
            0.0 (
y/'-'.i )
o .

?


?' .
i
(5
3
r
r~ "
CO (o/:..i)
\J & G
O ^7

0.0%
NOX (g/mi)
^. ^^
<9. y?
^.^ ;
o.i i
0-3H
0.91
0,9,

-------
Calculations

The results of  the  test plan can be analyzed statistically to determine if the off-
sets  between the  various  test  groups  are real.   The variation  between  control
groups  vs.  experimental  groups  must  be statistically similar,  caused by  similar
effects in both groups.  This allows us to  ascribe the  offset  in  group  means to the
experimental parameter changed in the test procedure.

In the case of  the  fuel study the values of interest are summarized in  the  follow-
ing table:

                                                                           standard
    Fuel                HC(g/mile)    sample size    degrees of freedom     deviation
                                          ni              ni-1                Si

                                           6                5              .02

                                          10                9              .02

                                           5                4              .04

                o
The variance, s,   are equal  for  fuels 1 and 2  and the   hypothesis that  the means

of these fuel are equal is accepted with the T-stat test.
EPA
AMOCO-50
Wolfsburg
1
2
3
'.45
.42
.36
           xl ~ X2
     t =
                 sp2
           nl
     where, SP^, the pooled variance is


         SP2 =  (nrl)(S1)2 + (n2-l)(S2)2
                   (n1-l) + (n2-l)

     then,

          t = 2.90.

Now the critical  value  of t where the probability of not accepting a true hypothe-
sis is 1 out of 100 times (   = .01) is ^ 2.9768.  Our calculated t lies within the
bounds of our  critical  value.   We accept the hypothesis that the hydrocarbon emis-
sions generated or AMOCO-50 and EPA fuels are statistically similar.

The variances  between fuels  1  and 3 are not  equal but  may  be similar.   The F sta-
tistic will help us determine this by  knowing the variance,  the degrees of freedom
for each  sample,   and  the probability  of not  accepting  a  true hypothesis  we are
willing to accept.


-------
If  the  hypothesis is correct  that  the variances are  equal,  then the above  calcu-
lated F will be between  .0644  and 15.52.  They  are  similar  statistically.   The  cal-
culated T statistic therefore can be calculated with the pooled variance  sp2.

     t = 4.865

The  critical  t value  for     =  .01 is  +_ 3.2498.   The means  are  not equal.   The
hydrocarbon emissions  are different because  of the  difference in  fuels,  EPA  vs.
Wolfsburg diesel fuel.

The  hydrocarbon emission test variances for fuel 2  and 3 are again tested for  the
hypothesis of equality with the F statistic,


             S2
              2
     F    -    -   -   95
     h9,4 ~    2  ~  '  5
              3

where the critical values of F are .069 and 14.55 when     =.01.  The  variances  are
statistically similar.   The calculated t statistic  is -3.95 and the critical value
for t when    =.01 is /  3.0123.   The hydrocaron emissions are not equal  between  the
AMOCO-50 and Wolfsburg diesel fuels.

Similar F and t stat tests indicate several important facts; that the variance  for
the temp controlled vs. soak controlled vehicle are equal,  the  variance  between  Hot
LA-4s and  FTPs on both  vehicles are  equal  and that  hydrocarbon  emission results
between Hot LA-4s  and FTPs are similar  statistically.

The  use" of an analysis  of variance (ANOVA  in MIDAS  the MTS  statistical  service)
using fuel as the method  of stratifying the data groups,  indicates  that  there is a
difference in the  emission results between the  groups for  HC and

-------