Low-emission diesel engines – an equipment roundup

Truck and engine manufacturers appear to be on target to introduce new, cleaner diesel engines. The engines are being developed to meet the U.S. Environmental Protection Agency’s new, more stringent diesel emissions standards that go into effect in 2007 and 2010.
The 2007 regulations demand that both particulate matter and oxides of nitrogen emissions be reduced by 90 percent from current levels.
Particulate matter is formed by the incomplete combustion of fuel in diesel engines. Oxides of nitrogen are formed in small amounts during combustion as a result of the combination of nitrogen and oxygen in the presence of high temperatures and pressures. Oxides of nitrogen are collectively referred to as “NOx”, where “x” represents a changing proportion of oxygen to nitrogen.
Engine makers Cummins, Detroit Diesel, International, Mack and Volvo have all reported that they will use cooled exhaust gas recirculation (EGR), along with diesel exhaust particulate traps, to meet the 2007 standards. Previous reductions in particulate matter emissions had been achieved through engine combustion improvements and oxidation catalysts.
EGR systems capture exhaust gases, pass them through a cooler and then mix them with the incoming air charge to the cylinder. This adds heat capacity and reduces oxygen concentration in the combustion chamber by diluting the incoming air with the cool exhaust gases. During combustion, this has the effect of reducing the combustion temperatures, which in turn, reduces NOx emissions.
Exhaust particulate traps filter and “catch” the particulate matter from the exhaust stream and prevent these particles from reaching the atmosphere. Over time, these traps “fill up” and need to be periodically “cleaned” by means of a regeneration process, otherwise the engine’s performance and fuel economy is adversely affected. This regeneration process is typically achieved by “burning off” the trapped particulate matter.
Caterpillar is the only engine manufacturer to use a different technique to reduce emissions. Its process is called ACERT, which stands for Advanced Combustion Emission-Reduction Technology. It employs a mix of injection, combustion and electronic tools, along with exhaust aftertreatment.
Interestingly, none of the filtration technologies planned for the new 2007 exhaust emissions standards will function with today’s diesel fuel. Consequently, the U.S. EPA has decreed that beginning Sept. 1, 2006, ultra-low-sulfur diesel fuel must be available nationwide. Fuel low in sulfur produces less particulate matter from combustion.
This fuel standard will be phased in through Sept. 1, 2010. The sulfur content of this new fuel will be dramatically reduced, from 500 parts per million (ppm) to just 15 ppm.
If that were not challenging enough for the petroleum industry, the new ultra-low-sulfur diesel fuel requires different and additional refining methods, transportation means and storage facilities.
All of this will, obviously, push up fuel prices. How much is anyone’s guess, although Cummins has projected the increase to be around $0.05 per gallon.
New specifications are being developed for lubrication oil compatible with the new 2007 and 2010 low-emissions diesel engines.
Real-world tests of the 2007 engines are expected to get underway sometime next year. The testing will be conducted with prototype, pre-production engines. This will give the engine and truck manufacturers the time and leeway to work out the inevitable problems that accompany any new technology.
It is a given that the new emissions-compliant diesel engines are going to be more expensive. Here again, no one knows just how much more. Estimates range all across the board, from a low of $1,500 to a high of $10,000.
Another unknown is how these engines will perform. Reliability, durability, driveability, performance, fuel consumption and operating and maintenance costs will be determined through time and experience. BI
Equipment news
ArvinMeritor has launched its Technical Training and Product Service Web site to provide training and service information on its Meritor, Meritor WABCO and Gabriel brand products. training.arvinmeritor.com
International has introduced what it claims is the “world’s biggest production pick-up truck for commercial business owners.” Based on International’s severe-service trucks, the CXT comes standard with all-wheel drive, air brakes, crew cab that seats five, International DT 466 diesel engine and Allison automatic transmission. navistar.com
Kenworth had the highest ranking in customer satisfaction among vocational Class 8 truck owners, according to J.D. Power and Associates’ 2004 Heavy Duty Truck Customer Satisfaction Study. Areas studied included ride, handling, serviceability, visibility and ease of entry and exit. kenworth.com
National Truck Equipment Association’s revised Truck Equipment Handbook contains technical and regulatory information on commercial vehicles, and has a comprehensive glossary of truck equipment terminology. To order, call 800/441-NTEA.
Peterbilt’s Model 335 is now available with the two-pedal automated Eaton six-speed UltraShift transmission (driver uses only an accelerator, brake and dash-mounted controls to initially engage forward or reverse); Models 357, 378, 379 and 385 are available with drivetrain combinations of Allison automatic transmissions and all heavy-duty Cummins and Caterpillar engines. peterbilt.com
Shell’s Rotella Extended Life Coolant Kit can switch a heavy-duty diesel engine from standard coolant to organic-based extended life coolant without having to completely drain and refill the cooling system. rotella.com
Volvo Trucks North America has revamped its Web site, adding a variety of new features and additional information on vehicles, services, F&I, training, etc. volvotrucks.us.com