The benefits of clean
diesel technology are expanding diesel’s
economic and industrial contributions. Through the use and development
of new clean technologies, the diesel industry is crossing a historic
milestone in 2007—one that is putting this famous workhorse on
par with some of the most advanced, clean and energy-saving solutions
of the future.
In January, U.S. truck and engine manufactures will begin producing
the most advanced, clean technology ever produced for heavy-duty
trucks and buses. And in October, the first milestone on the Road
to 2007 took
place when Ultra Low Sulfur Diesel (ULSD) fuel arrived at fueling
stations nationwide. Clean diesel will play a leading role in helping
states meet strict new air quality goals set by the U.S.
Protection Agency (EPA). Today’s trucks and buses already produce
only one-eighth the tailpipe exhaust compared to those built in
1990. New engines will be even cleaner: It would take 60 trucks
built in 2007
to equal the soot emissions of one truck sold in 1988.
The diesel industry is leading the way in America’s path toward
cleaner air and energy conservation. Recently, the EPA unveiled
the first-ever series hydraulic hybrid diesel urban delivery vehicle,
which will provide
dramatic improvements in fuel economy and emissions reductions.
The development of the hydraulic hybrid is the result of a partnership
between the EPA, U.S. Army, International Truck and Engine Corp.
(International), Eaton Corp. and UPS. The EPA and UPS plan to evaluate
fuel-economy performance and emissions during a series of tests.
In laboratory testing, the EPA’s patented hydraulic hybrid diesel
technology achieved a 60- to 70-percent improvement in fuel economy,
than a 40-percent reduction in carbon dioxide emissions, compared
to a conventional
EPA and our partners are not just delivering packages with this
UPS truck—we are delivering environmental benefits to the American
people,” said EPA Administrator Stephen L. Johnson. “President
Bush is moving technology breakthroughs from the labs to the streets.
We are doing what is good for our environment, good for our economy
and good for our nation’s energy security.”
The EPA cited laboratory tests showing that the technology has
the potential to dramatically improve the fuel economy of urban
vehicles used in applications such as package delivery, shuttle and transit
and refuse pick-up. It estimated that when manufactured in high
volume, the added costs of the hybrid components could be recouped in
three years through lower fuel and brake maintenance costs.
In the series hydraulic hybrid diesel, a high-efficiency diesel
engine is combined with a unique hydraulic propulsion system, replacing
the conventional drive train and transmission. The vehicle uses
hydraulic pumps and hydraulic storage tanks to store energy, similar
to what is
done with electric motors and batteries in hybrid electric vehicles.
Fuel economy is increased in three ways: Vehicle braking energy
is recovered that normally is wasted; the engine is operated more efficiently;
the engine can be shut off when stopped or decelerating.
Diesel engines have become the powertrain of choice for heavy-duty
pickup truck buyers in the United States because they provide more
torque for maximum towing and hauling with improved fuel economy.
Industry-wide diesel heavy-duty pickup and chassis sales from 1994
to 2006 grew
an average rate of nine percent per year, according to R. L. Polk & Co.
In 2006, 69 percent of these trucks sold were diesel-powered.
UPS, International and Eaton have been working with the EPA and
the U.S. Army’s National Automotive Center on the hydraulic technology
for several years. So what exactly are Green Diesel Technology® Vehicles?
Let’s take a closer look.
What is the technology in Green Diesel Technology vehicles?
This new technology utilizes the benefits of a catalyzed diesel
particulate filter and ULSD fuel in combination with an exclusive
International engine performance design that significantly lowers the
odor of diesel-powered buses and trucks.
Are Green Diesel Technology buses and trucks currently available?
International manufactures Green Diesel Technology school buses
and trucks, and provides Green Diesel Technology retrofit kits
for late-model diesel vehicles. Green Diesel Technology school
buses have been in service
in California since 2000. International’s no-smoke, no-smell diesel
vehicles and retrofits are available to customers in markets in
which diesel fuel with sufficiently reduced sulfur content is available.
How does this new technology work?
International’s modern, highly efficient engine with advanced hydro-electronics
is the heart of the technology. Engine combustion is optimized
to lower nitrogen oxide emissions by approximately 25 percent. The vehicle
fueled with ULSD fuel. A catalyzed diesel particulate filter replaces
the ordinary muffler. This three-level technology system makes
it possible to cut gaseous hydrocarbons and particulate emissions by
99 percent from
previous levels, to near-zero levels. International’s Green Diesel
Technology vehicles, using this system, will comply fully with
2007 federal rules.
Will this technology affect the life of the engine?
The service life of the engine will not be compromised in Green
Diesel Technology vehicles.
What does the California Air Resources Board (CARB) say about Green
Diesel Technology school buses?
The California regulatory board in 2001 certified the clean-air
Green Diesel Technology school bus for inclusion in its program
to retire older buses from school districts. Under the CARB’s current
rules, the Green Diesel Technology school buses are qualified to
share in state
funding of new bus purchases by school districts.
What is the federal regulatory position on Green Diesel Technology
The Green Diesel Technology system has been certified by the federal
agency. At an official ceremony in Washington, D.C., International
was recognized by the EPA for producing a diesel engine that meets standards
for particulate and hydrocarbon emissions six years earlier than
Can Green Diesel Technology school buses be delivered to customers
outside of California?
Patrick Charbonneau, International’s vice president, regulatory
and technology affairs, stated, “Schools can continue to rely on
the power and fuel efficiency of diesel buses, while helping to
make their clean air goals. We can deliver these Green Diesel Technology
not only to California, but to other parts of the country where
the fuel is available.”
How has International achieved this clean-air diesel breakthrough?
The Green Diesel Technology vehicle breakthrough is the next step
toward diesel power without pollution. International has taken
its high-performance, low-emission engine and fitted it with a
special converter that runs
on ULSD fuel. The results: Particle emissions are reduced by more
than 90 percent, which exceeds the stringent truck-emissions standards
by the EPA. And it is better than the emissions of the next best
Can older vehicles be retrofitted to meet new requirements?
Yes. It is feasible to retrofit recent model diesel vehicles with
filters to reduce particulate matter. Factors that affect retrofitting
include geographic location, duty cycle and engine type. International
is examining the best way to provide retrofit options to its customers.
What about diesel exhaust and health effects?
No scientific study demonstrates a causal link between diesel emissions
and health effects in humans. One set of studies, involving coal
miners, focused on diesel as the primary particle source to which individuals
were exposed; it found no adverse health effects.
There have been stories in the media covering the alleged effects
of diesel exhaust on children who ride school buses. Are these stories
Two reports stimulated media publicity in 2001 and 2002. Independent
scientists, including the American Council on Science and Health
(ACSH), said the reports were unreliable. One study used diesel buses
at least 15 years old, one of which was likely in serious disrepair.
The studies used questionable methods to collect the data and draw
inferences about the results. A more reliable study by public school
Fairfax County, Va., using more accurate and reliable investigating
techniques, found no risk to bus drivers or to student passengers.
What about fire and safety hazards associated with diesel fuel?
Diesel has the clear advantage. Compared to gasoline or natural
gas, diesel fuel is safe, stable and easy to use, and requires
no special handling or storage. Since natural gas is highly flammable,
of fires and explosions is always present, so it must be stored
and handled extremely carefully.
What can be done to reassure customers about diesel and health
Sound science is needed to make rational judgments. International
is a leading supporter of scientific research, working with the
EPA, the Health Effects Institute and others. Customers should know the
fact: No scientific research has ever shown that exposure to diesel
emissions causes increased health risks.
Air pollution in the form of particulate matter has been associated
with increased health risks. However, diesel engines are only one
of a great many possible sources of particulate matter; others
natural gas and electric power plants, just to name a few. Also,
since today’s new diesel engines already show at least a 90 percent
reduction in particulate matter emissions since 1988 and are heading
emissions—it’s pretty clear that diesel particulate matter
emissions are a decreasing factor in particulate air pollution.
New research by California government regulators indicates that
low-emitting diesel vehicles may have significant environmental
advantages over comparable natural gas vehicles. The study conducted
by the CARB
produced the following findings:
• In eight of 11 categories tested, a low-emitting diesel bus powered
by low-sulfur fuel and equipped with a particulate trap produced
lower levels of pollutants than a similar transit bus powered by natural gas.
• Natural gas vehicle exhaust was eight times more mutagenic than
diesel exhaust. (Mutagenicity measures the degree of mutation in
a cell or organism and is used as a potential health-risk indicator for cancer
and reproductive health effects.)
• The natural gas bus discharged more particulate mass, hydrocarbons
and carbon monoxide than the low-emitting diesel bus.
These new findings are supported by other comparative studies of
clean diesel and natural gas, including a comprehensive study conducted
by Ecotraffic of Sweden, which found that diesel vehicles have
lower greenhouse gas (GHG) emissions than natural gas, thanks to
superior fuel efficiency. Similarly, a fuel comparison study conducted
by the Harvard Center for Risk Analysis in 2000 noted that, “The
use of natural gas as a motor vehicle fuel may exacerbate the greenhouse
gas effect because methane will escape into the atmosphere during
refueling operations and at natural gas storage facilities.” The
Harvard study also noted that methane is approximately 20 times more
as a GHG than carbon dioxide.
All things considered, the partners behind the hydraulic hybrid
technology are optimistic about its potential.
The hydraulic hybrid technology is quite promising and we’re eager
to see how the vehicle performs in a real-world setting,” said
John Beystehner, chief operating officer of UPS.
As for Eaton Corp., the company has been working with the EPA since
2001 under a cooperative research and development agreement involving
hydraulic hybrid systems. As part of the company’s role in designing
and developing hybrid technologies, Eaton engineers have been co-located
at the EPA’s Ann Arbor, Mich., facility. Eaton is also working
on a number of other hybrid vehicle initiatives with UPS, International
Eaton sees the series hybrid as a natural and exciting progression
in the development of hydraulic hybrid systems,” said Craig Arnold,
Eaton senior vice president and president, Fluid Power Group. “We
are continuing to develop a number of hybrid hydraulic and hybrid
electric vehicle technologies with wide-ranging customer applications.
committed to working with the EPA, our industries and our customers
to create a cleaner, brighter future.”
Hal Morgan is the director of research and education for the Taxicab, Limousine
and Paratransit Association.