In light of the continuing rise in gasoline prices, the diesel push by Mercedes-Benz could signal an industry shift in that direction. But it will take work, investment and care to maintain the momentum and accelerate the development of more diesels.
Much of the responsibility rests with automakers. Mercedes-Benz plans to launch several diesel-powered vehicles in all 50 states as early as 2008. Mercedes plans to use urea to neutralize oxides of nitrogen so its diesel can be as clean as gasoline engines.
Some regulators correctly worry that the system will fail if consumers don't replenish on-board urea canisters. So it behooves Mercedes to redouble efforts to make the urea refilling process foolproof and easy to use.
But government has a role, too. The Bush administration must lean on the oil refineries to increase and improve the supply of the low-sulfur diesel fuel that is needed to meet Tier 2 standards. And the EPA must not set up roadblocks, such as unreasonable requirements involving the urea used in the emissions-control system.
Volkswagen has been trying but struggling to sell diesels in a range of vehicles.
The Chrysler group also is likely to put diesels in at least a couple more models, such as the Chrysler 300 and Jeep Grand Cherokee, and other automakers are moving in the same direction.
A word to the wise to GM and Ford: Don't drag your heels on diesels the way you did on gasoline-electric hybrids. Limiting diesels to big pickups could be a mistake. GM and Ford must be into all the major fuel-saving technologies, including diesels and hybrids.
Diesels won't dominate the industry, but they can exist alongside hybrids and other alternative powerplants that burn hydrogen or natural gas.
The result will be a healthy range of choices for the consumer.