Sulfur neutralizes these new control technologies and would prevent new vehicles from providing air quality benefits. Equally important, reducing fuel sulfur also reduces emissions from existing vehicles, because the millions of trucks and buses already on our roads will all be running cleaner as soon as they begin using this cleaner fuel. These engines will require new emission control systems similar to those that the heavier vehicles will need to meet the standards in this rulemaking. If the fuel sulfur level is too high, automakers will not be able to market this new technology at all. Considering their potential for dramatically reducing greenhouse gases and increasing fuel economy, it is critical that the U.S. preserves the possibility of using this type of engine in the future.
Many promising developments are under way now to show how clean diesel can be.
The Alliance supports EPA's proposal as a good, first step toward making diesel vehicles clean. The proposal needs to go further, however, to fully enable the new technologies. We also seek changes in other fuel parameters, as recommended in the World-Wide Fuel Charter. The Charter is a consensus document endorsed by automakers from around the world that specifies appropriate fuels for different vehicle technologies. Although automakers believe the rule does not quite go far enough, they do believe it goes far enough to stimulate further development of the new technologies, which still need refinement before they can become commercially viable.