BMW_118d

Despite all the hype behind hybrids and fuel cells the last few years, the answer to the riddle of how to get cleaner air and import less oil may come most immediately from a familiar technology: diesel vehicles. Stricter new U.S. fuel economy regulations were officially passed into law in December - they are expected to be aligned with new Canadian ones in 2011 - and auto makers the world over are looking at diesel vehicles as the quickest and often least expensive way to meet new mileage and emissions rules.