EPA Emission Regulations
How will Changes in the EPA Regulations
Affect Custom Fire Apparatus Chassis?
Changes in the EPA Emissions Regulations for heavy-duty trucks has caused confusion
throughout the trucking industry for several years. This document is meant to provide the
fire fighting community with a general discussion of those facts that fire apparatus
manufacturers and engine suppliers can all agree on.
Overview
New EPA emissions standards for all on-highway diesel truck engines go into effect January
1, 2004. Due to alleged past violations, Caterpillar, Cummins, and Detroit Diesel signed an
EPA “consent decree” which, among other things, requires them to meet the 2004 standards
15 months early (October 1, 2002). This accelerated schedule affects all diesel truck engines
with the greatest immediate impact on the heavy-duty models.
Truck Engine Emission Standards (g/bhp-hr)
NOx
Particulates
NMHC
CO
1990
6.00
0.60
1.30
15.50
1991
5.00
0.25
1.30
15.50
1994
5.00
0.10
1.30
15.50
1998
4.00
0.10
1.30
15.50
2004
2.50
0.10
0.50
15.50
2007
0.20
0.01
0.14
15.50
The new standards mandate a 40% reduction in NOx emissions relative to present levels. This
is a huge hurdle for the engine manufacturers, requiring large investments and significant
advances in technology. The picture is further complicated because some manufacturers have
sufficient emissions credits to allow them to gain additional time to become compliant. The
table above presents the emissions regulations changes since 1990.
The Technical Challenge
Reducing emissions in a diesel engine is the engineering equivalent to herding cats on the deck
of a sardine boat during a hurricane. Every move you make in one direction causes you to
lose control in another. The actions required to improve emissions of one pollutant will often
increase the emissions of another pollutant. Factors such as combustion temperature, fuel
timing, cylinder pressure,
chamber shape, rpm, load, boost
pressure, engine temperature,
swirl characteristics, etc… all
combine to create a very
complex soup of variables.
Engine manufacturers have
each taken somewhat different
approaches to solving the
emissions puzzle, but none are
solving it without impacting
the apparatus designers. The
following is a description of potential challenges that are being faced by custom chassis
manufacturers across the industry.
Engine Price Increases
The cost of engines is increasing by thousands of dollars across the board. This is due to
the cost of emissions components as well as the amortization of engineering development,
testing, and tooling expenses.
Cooling Package Cost Increases
Generally speaking, the emissions changes are increasing the amount of heat that
must be removed through the chassis cooling system. This may mean larger
radiators, larger charge-air-coolers, more plumbing, larger fans, new shrouds, extra
coolers, etc… Every new or bigger component comes at a cost.
Exhaust System Additions
In some cases the new engines will require catalytic mufflers.
Weight
New emission control components, larger radiators, more coolant, all will mean a heavier
power train. Apparatus manufacturers will need to account for this additional weight by
paying close attention to front axle ratings, particularly in the more marginal applications
such as heavy ladders and platforms.
Heat
In addition to the extra heat
dissipation through the cooling system,
emissions components may be
emitting more heat directly into the engine
compartment. Intake manifold air
temperatures will be just as critical as engine
coolant temperatures. Higher under
hood temperatures have the potential to
cause AC systems to work harder to cool the cab to the same level as today.
Packaging
Additional emissions components and larger radiators may force the apparatus manufacturer
to increase the height and/or width of the engine tunnel.
Horsepower Ratings
Several engine models will no longer be available at the same ratings that they are today.
Some ratings will be limited to operating at the high horsepower rating for short periods of
time.
Fuel Economy
It is likely that fuel economy will suffer by 2% to 4% compared to the same
engine and rating today.
Oil Specifications
Engines using exhaust gas recirculation as an emissions reduction strategy will require a
higher grade of oil than today.
Throttle Response
One bright spot is that throttle response should be the same or better than
today. Those manufacturers employing variable geometry turbo chargers
may see quicker throttle response.
Maintenance Issues
There is the potential that oil change intervals will be reduced.
Future Concerns
The emissions requirements make another significant leap in the year 2007. Additional
measures will be required by the engine OEMs to meet these standards, which may include
larger catalytic mufflers and particulate traps.
Summary
Significant engine changes will occur over the next few years due to new EPA emissions
standards. These changes are expected to result in increased engine cost and complexity. On
the positive side, we should all have cleaner air to breath. FAMA manufacturers engaged in
designing custom cabs and chassis understand these challenges. Contact your manufacturer’s
representative to learn more about how EPA regulations will affect the future of fire
apparatus.