Questions remain with new engines
Nov 1, 2002 12:00 PM, Editorial By Charles E Wilson
ONE OF the biggest challenges facing tank fleet managers over the next year is deciding how soon to buy new trucks with the post-October 2002 heavy-duty diesel engines. This may be one of the most difficult decisions fleet executives have had to make in decades.
The reason is that radical design changes were needed to enable the engines to meet the latest emission reductions mandated by the Environmental Protection Agency (EPA). There is uncertainty in the field about how the redesigned engines will perform over the longhaul.
That is quite a contrast with the way pre-October 2002 engines are viewed. Diesel engine technology had reached a high point in terms of efficiency and reliability. Tremendous strides were made during the 1980s and 1990s in heavy-duty diesel engine design. The manufacturers did an outstanding job of designing and building engines that routinely deliver a million miles of trouble-free performance before needing an overhaul. Fuel economy is in excess of six miles per gallon for engines that are properly maintained.
All of that progress and achievement were thrown into flux with the post-October 2002 engines. Exhaust gas recirculation (EGR) is the main concern. Virtually all of the post-October 2002 engines now on the market require EGR.
The new engines come with a price tag that is as much as $10,000 higher than the power plants they are replacing. In addition, fuel consumption has increased as a result of new emission reduction components. Engine life is a question mark now, as is resale value.
The new engines use EGR to control nitrogen oxides emissions by sending exhaust gases back into the combustion chamber to be burned a second time. The amount of exhaust gas introduced into the combustion chamber displaces oxygen, creating cooler combustion, which reduces emissions reportedly associated with health risks.
As part of the process, engine coolant absorbs some of the heat before the recirculated exhaust gas enters the combustion chamber. As a result, the engine cooling system runs hotter, as do other engine components.
With all of the concerns, it's not surprising that many fleet managers are doing their best to avoid the new engines. Some have reacted by purchasing additional new trucks before the October 2002 deadline. Others are turning to the used truck market. Cycle times are being extended on trucks already in service.
These are all short-term solutions, made palatable by a slow economy. Sooner, rather than later, the economy will heat up and fleets will need new trucks. Problems with the post-October 2002 engines will be worked out, hopefully before the next round of federally mandated emission reductions.
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