For a while there, it looked like the diesel engine was on the ropes. Accelerated emissions requirements for 2002 and 2004 presented real problems for heavy-duty diesel manufacturers and raised serious questions about engine performance, durability and just general friendliness in truck applications.
With California in the lead, many states with air quality problems started talking about restrictions and even outright bans for diesel-powered trucks and buses in urban settings. High initial price and perceived operating difficulties kept diesels from making larger inroads into light trucks, and diesel-powered passenger cars, never too popular in North America, just about completely faded away with sustained low prices for gasoline.
There have been some advances in alternative powerplants, but none comes close to the durability and fuel-efficiency of the diesel engine. Without viable alternatives, fleets of all types would be in serious trouble if they lost the operating advantages of diesel power.
While the diesel may have been down for the count, it is decidedly not out, and in fact seems to be roaring back into contention as the heavy-, medium- and light-weight champion for environmentally sound automotive power. The reason for the turnaround is twofold: major advances in diesel technology; and a more balanced understanding of environmental impact that looks at the entire picture, not just a few isolated standards.
About half the stories in a recent issue of Ward's Engine and Vehicle Technology Update covered new diesel technology. A new integrated fuel pump/injector has allowed Volkswagen to generate 150 hp. and 321 lb.-ft. of torque from a 1.9L 4-cyl. diesel that delivers 53 mpg in a small sedan. The engine, already commercially available in Europe, out powers many 6-cyl. gasoline engines and even small V8s.
In a second story, the newsletter reports that the majority of public bus agencies in Northern California have chosen “clean diesel” over CNG-powered engines for their new buses, largely because those diesels will cost less to buy and operate, while generating even lower particulate emissions than the CNG.
Other stories talk about diesel's advantages over gasoline engines in controlling carbon dioxide (CO2 ) emissions (now recognized as a major greenhouse gas), advances in particulate trap controls, and the environmental impact of diesel's fuel efficiency advantage in light trucks and SUVs.
And FLEET OWNER has reported extensively on the progress in diesel technology that will allow engines to meet emissions requirements in ’02, ’04 and beyond.
Otto Diesel patented the engine that bears his name in 1892. In the next 100 years, it developed gradually into a dependable, efficient vehicle power source. In the last decade, however, that development curve has taken an exponential turn upward and shows no signs of leveling off any time soon.
That's good news for trucking, which needs the power, long life and efficiency, as is the growing public recognition that the diesel makes both economic and environmental sense for vehicles of all sizes.