Gasoline Beats Diesel for Cleaner Autos, Study Says
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 for cutting U.S. oil use and polluting emissions linked to global warming, according to a report in Reuters on January 6.
The study, from the Union of Concerned Scientists, 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.
For example, it would cost a consumer about $2,800 over the price of today's vehicle for an improved diesel that could cut oil use by about 30 percent. That's 2.5 times more than it would cost to achieve the same reductions with an improved gasoline vehicle, the report found.
The higher price of both improved diesel and gasoline vehicles are more than offset by reductions in fuel costs, on balance saving consumers between $400 and nearly $2,000 over a vehicle's useful life, the report said
In all cases, the report finds that improved gasoline vehicles save consumers more money because of their substantially lower initial price tag.
"New pollution controls may one day clean up diesel's dirty image," said Patricia Monahan, a senior analyst in UCS's Clean Vehicles Program and lead author of the new report. "But, head to head, our report shows that improved gasoline vehicles are the better buy," she said.