WASHINGTON, DC - Gasoline-powered vehicles and hybrid cars that run on both gasoline and electricity will be more cost-effective than diesel engines for the foreseeable future in cutting U.S. oil use and emissions pollution linked to global warming, according to a recent Reuters report. The study, from the Union of Concerned Scientists (UCS), comes as automakers and their allies in Congress promote diesel engines, despite poor sales in the U.S. market, as a way to address concerns about oil dependence and global warming. "Proponents should not oversell diesel technology as a silver bullet," said David Friedman, research director for UCS's Clean Vehicles Program and a co-author of the new report. "While diesels may eventually shed their image as an industry black sheep, they still can't match the pollution performance of today's cleanest gasoline cars." In its report, the group used detailed modeling to examine for the first time how diesel and gasoline vehicles competed among a variety of cars and trucks, applying improved engines and other conventional fuel-saving technologies that could be implemented today, as well as advanced and hybrid technologies that could be implemented within the next 10 to 15 years. Improved diesel and gasoline vehicles could reduce oil use compared to today's vehicles by as much as 40 percent using conventional technology, and hybrid-electrics could cut oil use by as much as 50 percent, according to the report. However, the sticker price of diesel-run vehicles for similar reductions would be higher than improved gasoline and hybrid gas-electric vehicles. In all cases, the report finds that improved gasoline vehicles save consumers more money because of their substantially lower initial price tag.