A big reason for European support of 'diesel-powered vehicles is that fuel taxes are heavier on gasoline,' McCurdy noted, adding that in 'the U.S., diesel fuel is more expensive than gasoline and is taxed at a higher rate. Anything that can be done to lower the cost of diesel fuel will help encourage consumers to consider purchasing a clean diesel vehicle.' Another reason is that there's less refining capacity of diesesl fuel in the United States, compared with regular gasoline. In August, diesel fuel averaged $4.30 a gallon -- $0.52 more than gasoline, according to the Energy Information Agency. But the price gap has narrowed. On Monday, diesel fuel averaged $3.96 nationwide, compared with $3.72 for gasoline. The Internal Revenue Service recently announced that a new diesel Mercdes-Benz vehicle and VW's Jetta diesel models are eligible for clean vehicle tax credits and is expected to add other models to list of eligible vehicles for tax credits. McCurdy noted that there are nearly 5 million diesel vehicles on U.S. roads, most big trucks. 'Over the next year automakers will launch more than a dozen new clean diesel car and truck models that meet the world's strictest clean air standards,' McCurdy said. 'By providing dramatic increases in fuel efficiency -- 20 to 40 percent better than comparable gasoline engines -- clean diesel vehicles can play a vital role in reducing U.S. oil consumption and reducing new vehicle CO2 emissions.' J.D. Power and Associates has forecast that diesels will account for 14 percent of the U.S. auto market in 2017, up from 3 percent today. That level of market penetration would save more than 29 billion gallons of gasoline, and reduce CO2 emissions by over 250 million metric tons, cumulatively over the lifetime of these vehicles, McCurdy said. Margo Oge, director of the Environmental Protection Agency's Office of Transportation and Air Quality, has touted diesels as a part of the solution. 'Diesel passenger vehicles are one important piece of the future technology puzzle,' she said. 'Clean diesel is a viable, efficient technology to help improve our air quality and energy security.' You can reach David Shepardson at (202) 662 - 8735 or dshepardsondteom.