Automobile Magazine (Enlarge photo)

28/06/2008 06:31. More so than most auto manufacturers, Mercedes-Benz has been committed to diesel engines, which are inherently more fuel-efficient and often deliver more torque than their gasoline counterparts. Diesels can have downsides, however, including low power output, dirty exhaust, and a characteristic clatter.

Modern diesels have dramatically curtailed these negatives while preserving their efficiency advantage. But although the engines are very popular in Europe, many automakers are unable to sell them in the United States because of U.S. emissions regulations, which are not only very strict but differ from one state to another. This year, for instance, seven northeastern states (Connecticut, Maine, Massachusetts, New York, Pennsylvania, Rhode Island, and Vermont) have adopted California's... // Automobile Magazine