GM 2007i C4500/5500 KODIAK CHANGES
EFFECTIVE JANUARY 1, 2007
The 2007 Emissions Standards Challenge
All diesel engines produced after January 1, 2007 must comply with the new regulations requiring
the reduction of nitrogen oxide (NOx) and hydrocarbons (HC) by 50% and particulate matter (PM)
by 90+% over the current 2004 emission standards. Further reductions of NOx, HC and PM will
be required by 2010. You can be confident that GM medium-duty trucks with 2007-compliant
diesel engines will deliver optimum performance at the lowest possible cost of ownership. In fact,
some of our 2007 emissions technology has already been proven in over 60,000 Isuzu trucks
operating successfully in Japan for the last two years! To comply with the new regulations GM
was required to make significant changes to the engine, exhaust system, transmission, and rear end
while maximizing performance and economy. The purpose of this information sheet is to outline
on the Kodiak (C4500/C5500) product line the changes to major components, underscore the
improvements in capability, and highlight areas of concern.
Exhaust Gas Recirculation (EGR)
To provide and maintain the best engine performance and fuel economy while reducing the
nitrogen oxide levels for the 2007 emissions requirements, our engines will use an advanced
Exhaust Gas Recirculation (EGR) System and a variable geometry turbocharger.
Closed Crankcase System
The 2007 regulations require that all diesel engine emissions be reduced, including crank- case
gas. As a result, GM’s closed crankcase system reroutes ventilation gases back into the engine for
combustion. Because of the temperatures required for DPF regeneration (1000 degrees
Fahrenheit).
Diesel Particulate Filter (DPF)
To reduce particulate matter, a Diesel Particulate Filter (DPF) captures soot and larger sulfate
particles in a series of ceramic honeycomb channels as gas passes through the porous material, and
the particulates are trapped and accumulate on the channel walls.
DPF Regeneration
To prevent the DPF from clogging, the trapped particulates are burned off, and the filter is cleaned
using a high temperature (around 1700 degrees Fahrenheit in the Particulate Filter) regeneration
process that leaves a harmless ash and residue. In most instances the regeneration will be done
automatically as the truck is driven throughout the day and requires no involvement by the driver.
However, if vehicle operation does not produce exhaust gases that are hot enough for automatic
regeneration, a control light will indicate the need for regeneration, and the driver may initiate the
process by activating a switch on the dashboard.
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Regeneration requires managing and controlling much hotter exhaust gases than those experienced
on current diesel-powered vehicles. By utilizing dual-well exhaust pipes, insulated catalysts and
filters, GM is able to retain the heat within the exhaust system. Because of the regeneration
temperature GM has developed an exclusive exhaust cooler system that will reduce the exhaust
temperature to current exhaust temperature levels (approximately 575 degrees Fahrenheit).
Consequently, pipe and component exterior skin temperatures are comparable to existing gas
engine exhaust systems. Even though the DPF filter is designed for long life, eventually the
accumulated ash must be removed by special cleaning equipment at truck dealerships.
Special Fuels & Lubricants
The EPA has also lowered the limit for diesel fuel sulfur from 500 ppm (parts per million) to 15
ppm for diesel engines that meet the 2007 emissions standard. This new ultra-low sulfur fuel
(ULSD) will be available beginning October 2006 and may add $.05 to $.10 per gallon to fuel
costs. A low ash lubricant is also required for use in the new engines. After January 1, 2007, 80%
of the diesel produced must be ULSD. The remaining quantity will be low-sulfur diesel and will
be available primarily for the Class 8 trucking industry.
Component Details
Engine
- 6.6L engine will increase to 330 HP and 620 lb/ft. torque
- Significant changes to engine components (e.g. closed crankcase cooling)
Exhaust System
- Diesel Particulate Filter (DPF) in exhaust system to capture particulates
- Regeneration process is used to burn off excess particulates
- Exhaust cooler needed to lower exhaust temperatures to 575 degrees Fahrenheit
Transmission
- GM signed up for the Allison Edge Program giving GM a 6-speed transmission and 30K
GCWR
- Transynd fluid will be standard in the Allison transmission
- 6th gear ratio will be .61 for better fuel economy
Rear End
- Selection of 4.63 rear end gear ratio to optimize fuel economy and “quiet” ride
characteristics for shuttle bus and RV applications
Miscellaneous
- Dual 150 amp alternator will be available (KH5)
- New rear stabilizer bar
- Riveted rear suspension is standard
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Areas of Concern
Cost
-
Cost for the emission will add $3000-$5000 to the cost of the vehicle
Life cycle cost will be higher – must use more expensive low ash lubricants for oil
changes, servicing of DPF cost to be determined
New emission trucks must use low-sulfur fuel.
Pre-emission trucks may use ULSD but may see up to a 5% decrease in fuel economy
The new emission system increases the vehicle weight by approximately 50 pounds
Exhaust System Temperature
- Exhaust pipe surface temperatures may be higher – temperature mapping for exhaust
system will be furnished by GM in the near future
- Exhaust cooler will be near the exhaust tip and may require body modifications to
accommodate
Servicing of Exhaust System
- DPF will require servicing at about 100K miles – the service interval will vary based on
average ambient temperature, operating conditions and idle time
- Servicing of DPF must take place at a GM service facility – this is not do-it- yourself
- There is a driver communication system – lights on the dash are not a suggestion
…green light there is a change in engine noise indicating that the vehicle is in regeneration
…yellow light means that the DPF is dirty
…red light means that the DPF is at capacity and the engine goes into limp mode
Gas Engines: A Viable Alternative
Our gas engine alternative is part of a complete line-up that is unmatched in the industry. Gas
engines provide a realistic solution to lower mileage users who appreciate the availability of fuel
at every gas station. GM gas engines are also compatible with alternative fuels using after-market
installations.
Impact on Pre-2007i Diesel Engines
Ultra Low Sulfur Diesel (ULSD) will be used on the all-diesel vehicles given that it will be the
only fuel available after the first of the year. Fuel economy on the pre-2007i engines may be
reduced by up to 5% when using ULSD.
Notes on CAT Engine
CAT engine validation is ongoing and should be complete the end of January 2007. Footprint will
be 25% larger than the current family of vehicles and there will be routing issues with the dual
PTO option (no change for passenger side PTO). There will be four hp power settings for the
CAT (207, 210, 230, 250). Production on the new CAT equipped truck will be in March 2007.
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