United States
Environmental Protection
Agency
Air and Radiation
EPA420-F-98-007
April 1998
Office of Mobile Sources
&EPA Environmental
Fact Sheet
Partnership for a New Generation of
Vehicles and the Environment
The Partnership for a New Generation of Vehicles (PNGV) is a 10-year
joint research and development effort between government and
industry. The Partnership was established in 1993 to develop new
automotive technology The goal is to design new technology that will
help reduce air pollution by tripling the fuel economy of typical family
sedans without sacrificing other important consumer attributes such as
safety performance, and affordable cost
PNGV: NewTechnology for a Low-C02 Car
The Partnership for a New Generation of Vehicles (PNGV) was an-
nounced by President Clinton and Vice President Gore as well as the Big
3 automakers (General Motors, Ford, and Chrysler) in September 1993.
PNGV Goals
Goal 1: Improve national competitiveness in vehicle manufacturing.
Goal 2: Implement fuel efficiency and emissions technology for use in conven-
tional vehicles.
Goal 3: Develop a vehicle to achieve up to 3 times the fuel efficiency of today's
comparable vehicle.
•Design a mid-size car which gets 80 mpg.
•Do so while maintaining the size, safety, performance, affordability, and
comfort of today's typical family sedan.
•Build prototype within 10 years.
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The central theme of the agreement is to
reconcile the automobile with the environ-
ment and at the same time, help ensure
long-term competitiveness of the domestic
auto industry. While today's new cars are
much cleaner and more fuel efficient than
those of 30 years ago, most of the advances
are based on improvements to basic auto-
motive technology invented a century ago.
To achieve the ambitious goal of designing
a 80-mile-per-gallon (mpg) mid-size sedan,
PNGV aims to develop "leapfrog" technol-
ogy rather than simply making minor
improvements on today's cars. The
program elevates environmental consider-
ations to the forefront of automotive
research and engineering. A successful
Partnership to develop a vehicle for the
21st Century would greatly reduce the
future risk of global climate change.
Cars and the Environment
Over the past century, personal vehicles
(cars, minivans, sport utility vehicles, and
pickup trucks) have enabled Americans to
enjoy unprecedented mobility. However,
this has a steep environmental cost,
primarily for two major categories of air
pollution: conventional emissions and
greenhouse gas emissions.
Conventional Emissions
Conventional emissions refer to air pollut-
ants known to have direct impacts on
human health. These include volatile
organic compounds (VOCs)—which
includes hydrocarbons (HC)—as well as
nitrogen oxides (NOx), carbon monoxide
(CO), and particulates. VOCs and NOx
together form ground-level ozone, the most
serious urban air quality problem in the
U.S. today. CO is a colorless, odorless gas
which reduces delivery of oxygen to the
body's organs and tissues. Ozone, NOx,
and particulates are lung irritants and can
contribute to health problems such as
asthma, breathing difficulties, and bronchitis.
Greenhouse Gas Emissions
Greenhouse gas emissions such as carbon
dioxide (C02) and methane are pollutants
which can "trap" heat radiated by the earth.
Many scientists believe greenhouse gases
have the potential to contribute to global
warming and view climate change as the
most serious long-term threat to the global
environment.
Transportation and Climate Change
Transportation contributes 1/3 of U.S. carbon dioxide
emissions and is the fastest-growing sector
U.S. Carbon Emissions
By Major Sector
Industry
(33%)
Transportation
(32%)
Buildings
(35%)
Carbon dioxide is the most important
greenhouse gas and is directly related to
fuel consumption. The near doubling of
U.S. new car fuel economy from the mid-
1970s to the mid-1980s essentially cut C02
emissions per car in half. Currently,
transportation (cars, trucks, aircraft, ma-
rine) accounts for almost one third of U.S.
C02 emissions and represents one of the
fastest growing sectors for greenhouse
emissions. Worldwide, vehicle green-
house emission trends are also of concern.
There is potential for explosive growth in
developing countries as these nations
develop more extensive road networks and,
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like developed nations, shift toward greater
use of cars to increase personal mobility.
To address global concerns on climate
change, the U.S. and 160 other nations held
international negotiations in Kyoto, Japan
in December 1997. The nations reached
agreement to reduce greenhouse gas emis-
sions from industrialized nations below
1990 levels by the year 2012. These discus-
sions have highlighted the need for reduc-
ing greenhouse gas emissions from motor
vehicles and greatly increased the interest
in highly fuel-efficient vehicles.
Vehicle Pollution and EPA
The U. S. Environmental Protection
Agency (EPA) has been regulating conven-
tional emissions like VOCs, CO, and NOx
On-Road Vehicle Emissions as a
% of U.S. Air Pollution
VOCs	NOx
| On Road Vehicles
|~| Other Sources
EPA National Air Pollution Emission Trends, 1900-1995, OAQPS, Oct. 1996
from motor vehicles since the early-1970s.
Today's new cars are approximately 95
percent cleaner per mile relative to new
cars of the 1960s due to technologies such
as catalytic converters, on-board comput-
ers, fuel injection systems, and evaporative
emission controls. Nevertheless, transpor-
tation still accounts for a large part of
national air pollution. On-road vehicles
alone contribute almost two-thirds of CO
emissions, about a third of NOx emissions
and more than a quarter of VOC emissions,
nationwide. In urban areas, the contribu-
tions from on-road vehicles are even
higher.
The federal government has no direct
standard for C02 emissions from motor
vehicles. However, since C02 emissions
are a direct reflection of fuel use, programs
which increase fuel economy will also
limit C02. As part of the Corporate Aver-
age Fuel Economy (CAFE) program, the
Department of Transportation and EPA
have regulated vehicle fuel economy for
nearly 20 years, and fuel economy levels
for cars have doubled since the regulations
were first established. Unfortunately, new
car fuel economy has not improved for the
past 10 years, so there has also been no
improvement in U.S. vehicle C02emis-
sions for a decade.
Increased Driving
A central challenge in the struggle to
minimize conventional and greenhouse gas
emissions from cars and trucks is the
growth in vehicle travel in the U.S.
Even though cars produce less pollution
per mile today than in the past, as Ameri-
cans buy more vehicles per household and
drive more miles each year, total pollution
levels rise. Historically, travel in the U.S.
has increased by 3 to 3.5 percent per year.
This means Americans have doubled the
total number of miles driven in the U.S.
every 20 years! Recent growth has been
about 2.3 percent per year, which would
lead to a doubling in about 30 years. To
keep overall vehicle pollution constant,
cars must pollute less per mile just to
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balance out the increased driving. To
actually reduce overall pollution, emis-
sions per mile must be cut significantly.
While tighter EPA vehicle standards for
conventional emissions have helped offset
increased driving, C02 control has not kept
pace.
vehicles, and pickup trucks which
consume more fuel and therefore emit
more C02; and
little consideration of truly renewable
fuels for transportation.
Americans are Driving More Miles
(trillion miles per year)
2.5 _
2.0
1.5
1.0
0.5
1950 1955 1960 1965 1970 1975 1980 1985 1990 1995
Increased C02
Unfortunately, in the U.S., several major
trends suggest C02 emissions from per-
sonal vehicles will continue to rise. These
trends include:
steady annual increases in driving over
the last 50+ years;
inflation-adjusted gasoline prices near
all-time low;
little consumer interest in fuel
economy relative to performance, size,
utility, and comfort;
the consumer shift from cars toward
larger minivans, sport utility
Environmental Benefits of
PNGV
By tripling the fuel economy rating of a
typical midsize car from around 27 mpg to
80 mpg, PNGV offers a great environmen-
tal reward. This fuel economy improve-
ment not only reduces a vehicle's fuel
consumption by 67 percent but also creates
the equivalent reduction in automotive C02
emissions. For example, a vehicle certified
at 80 mpg would emit just 112 grams of
C02 per mile—one third the C02 produced
per mile by a typical car today. (Actual
values will be slightly higher in on-road
driving.) This has ground-breaking impli-
cations since technology developed in the
U.S. could be applied worldwide to reduce
greenhouse gases.
None of the other major public policy
options for reducing automotive C02
emissions—higher gasoline taxes, higher
fuel economy standards, renewable fuel
requirements, or travel restrictions—is
politically popular. New technology that
avoids major trade-offs offers an attractive
path toward C02 emission reductions from
vehicles. A program like PNGV could play
a major role in any U.S. climate change
strategy.
At the 1998 Detroit Auto Show, automo-
tive manufacturers showcased a number of
high-efficiency concept vehicles which
utilize the same types of technologies
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being researched through PNGV. These
vehicles, along with manufacturer an-
nouncements during the Auto Show,
indicate both that research on high effi-
ciency vehicles is well underway, and that
one or more of these technologies will
likely be technically feasible in the PNGV
time frame.
In order to successfully meet the 80-mpg
goal of PNGV, a prototype vehicle must
demonstrate that it can meet even tighter
Tier 2 vehicle emission standards. The Tier
2 program was authorized by Congress in
the Clean Air Act Amendments of 1990,
which instructed EPA to determine
whether tighter standards for conventional
pollutants are necessary in order to protect
air quality. The Act suggested EPA con-
sider reducing current standards for HC,
CO, and NOx by a factor of two and
increase the definition of a vehicle's
"useful life" from 50,000 to 100,000 miles,
thereby keeping vehicles cleaner, longer.
Having a PNGV vehicle meet these tighter
emission levels represent a significant step
forward in terms of lower emissions. It
ensures successful PNGV technologies
will create not only the most fuel efficient
but also some of the cleanest personal
vehicles in the world.
In addition, PNGV could yield several
other environmental benefits since the
amount of oil exploration, drilling, ship-
ping, and refining would drop as fuel
consumption declined. Finally, the PNGV
program has established a goal of at least
80 percent recyclable components, another
step beyond today's industry average of
about 75 percent.
PNGV Advanced Technology
Research
The triple fuel economy objective involves
a long-term systems approach. Many
different technologies are now under
consideration, and it is impossible to
predict which of these technologies will
turn out to be the winner or, hopefully,
winners.
Building the Optimum PNGV Car
Primary Power
Source
Secondary
Power Source
Regenerative
Braking
Materials
Aerodynamic
Drag
mum Car
control
System

Transmission
Accessories
ciuaior
Clutch
Tire Rolling
Research on new PNGV automotive
technologies has been active at federal
agencies, national research labs, automo-
tive suppliers, universities, and private
industry since PNGV was announced in
late 1993. In January 1998, PNGV an-
nounced the selection of technologies
considered to be among the most promis-
ing to meet the goals for an 80-mpg PNGV
vehicle. The four areas highlighted by the
Partnership include the following:
Priority Research
• Advanced direct injection engines:
Researchers are studying piston engines
that incorporate advanced technology
features such as direct injection, turbo-
charging, multiple valves per cylinder,
lightweight materials, and novel methods
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of construction. Engines that are derived
from small diesels using conventional fuels
are receiving much interest, especially with
respect to NOx and particulate emission
control approaches. Other fuels are also
being investigated.
•	Fuel cells: This power source is a
substitute for the conventional internal
combustion engine in cars today. Fuel cells
convert hydrogen into electricity in a
simple system with no moving parts. In an
ideal system, the only by-product is water
vapor, and there is no other pollution. The
hydrogen used by fuel cells can be stored
directly (e.g., compressed in a tank) or
manufactured on-board from a fuel like
methanol.
•	Hybrid-electric vehicle drive: Hybrid
vehicles typically combine two different
types of power sources in a single vehicle
to take advantage of the unique benefits of
each source. PNGV researchers have
focused on both diesel-electric hybrids,
which would have both a diesel engine and
a battery, and gasoline-electric vehicles,
which would have both a gasoline engine
and batteries. Batteries vary in the amount
of driving range they allow a vehicle based
on their energy and power densities and
their charging/discharging efficiencies.
Most electric vehicles in the past century
have used lead-acid batteries, but research-
ers are developing advanced batteries such
as nickel-iron, nickel-cadmium, sodium-
sulfur, zinc-air, and lithium batteries,
among others.
•	Lightweight materials: Recent advance-
ments in strong, lightweight materials for
use in vehicles offer another way to reduce
fuel consumption while maintaining safety
and performance. Research on advanced
applications of aluminum, plastics, and
composites has also stimulated vehicle
weight reductions using more conventional
materials.
In addition to these areas of focus, the
Partnership has also been investigating
many other promising technologies, in-
cluding:
Power Sources
•	Gas turbines: Both metallic and ce-
ramic types of gas turbines are under
consideration. There is also interest in
configurations which integrate the prime
engine mover and an electrical motor/
generator.
•	Flywheels: Energy is stored and re-
leased in a flywheel system by the increase
and decrease of the rotational speed.
Advanced materials with high strength-to-
weight ratios are under consideration as are
configurations in which the flywheel is
integrated into the motor/generator. Like
other secondary power sources, cost,
reliability, efficiency, and safety need to be
assessed fully.
•	Ultracapacitors: Ultracapacitors are
devices for storing electricity like a battery.
Unlike a battery, however, they are de-
signed to release their energy in a quick
burst (ideal for starting or accelerating a
car) and they store energy quickly (ideal
for capturing the energy available when a
car is braking). Current work is concen-
trated on improving performance and
reducing costs.
•	Hydropneumatics: This is a mechani-
cal type of energy storage. Hydro-pneu-
matic systems store energy by using a
high-pressure liquid to compress gas.
These systems have high power densities
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(which allow a quick burst of energy, ideal
for vehicle acceleration) but have low
energy densities (meaning they only store a
small amount of energy.)
Reducing Energy Demand
•	Aerodynamic drag: Aerodynamic drag
is a measure of the resistance caused by air
as vehicles are driving. Drag increases in
proportion to the vehicle's speed squared
and depends on the size and shape of the
vehicle. Most efforts are going into ve-
hicle drag coefficient studies since re-
searchers are not expected to reduce the
frontal area for the PNGV car.
•	Tire Rolling Resistance: Tires vary in
the amount of friction they must overcome
as they roll. While friction can help with
driving traction, it also forces a vehicle to
use more fuel to overcome the friction
forces. Advanced tires with low rolling
resistance are designed to be more efficient
while maintaining safety and performance.
•	Accessories: Any use of accessory
devices on a car or truck—air conditioning,
heaters, radios, lights, etc.—consumes
additional fuel. Current research is exam-
ining ways to make accessories more
efficient while also exploring alternative
ways of powering these components.
Reducing Energy Losses
•	Regenerative Braking: One way to
reduce the amount of energy it takes to
drive a car is to save the energy usually
dissipated as heat during vehicle braking
and use it to help power the car instead.
This "regenerative braking" will use the
types of secondary power sources dis-
cussed previously to store and release this
otherwise-wasted energy.
• Other Losses: Consideration is also
being given to the possibility of recovering
some of the energy now lost as heat in
engine coolant and engine exhaust and
using it to help power the vehicle.
Alternative Fuels
Nonpetroleum fuels provide alternative
sources of energy to traditional gasoline
and diesel fuels. Promising alternative
fuels now used to power vehicles include
compressed natural gas, methanol, ethanol,
propane, dimethyl ether, hydrogen, and
electricity. Some of these can be produced
by renewable and/or domestic resources
such as wood, corn, or even garbage.
Renewable fuels have the potential to
provide additional greenhouse emission
reductions even beyond fuel economy
advancements, particularly if farmers and
fuel producers use renewable energy—
rather than fossil fuels—to power equip-
ment used in harvesting, transporting, and
producing renewable feedstocks and
renewable fuels.
For More Information
For further information on the PNGV
program, please contact the Advanced
Technology Support Division at:
U.S. Environmental Protection Agency
Office of Mobile Sources
2565 Plymouth Road
Ann Arbor, MI 48105
Additional documents on PNGV are
available electronically from the EPA
Internet server at:
http://www.epa.gov/OMSWWW/
pngvhome.htm
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