Recently passed energy legislation that mandates 40 percent fuel efficiency increases on automakers to 35 miles per gallon has them looking toward diesel, The Detroit News reports. General Motors Corp., Ford Motor Co. and Chrysler LLC have committed to a diesel option in the next generation of their light-duty pickups, which are the best-selling vehicles in each of their lineups. If all goes well and more consumers accept diesels as an option, the technology could expand beyond trucks. Diesel engines can improve a vehicle's fuel efficiency 30 percent; the fuel is readily available and millions of people drive diesels daily. Diesel engines also have a decades-longer track record than hybrids and are the choice among about half of all European car buyers. U.S. diesel vehicles are not widely available, have had difficulty meeting emission standards, are more expensive and face the dated stigma of smelly, noisy, sooty engines of the 1970s and 1980s. Chrysler's Jeep Grand Cherokee is the only model, outside of medium-duty pickups, with a diesel option among all three American automaker's lineups. And that vehicle can't be sold in California or the seven other states that have adopted stricter emissions standards than what's set by the federal government. According to The Detroit News, J.D. Power and Associates predicts the diesel market will more than double to 1.27 million units by 2012, and others in the industry expect diesel to make up 15 percent of the total automotive market within the decade.