Cleaner diesel fuel goes widely on sale in the United States this week under new standards that could be a big boost for air quality and may encourage the use of more diesel-powered cars in the US market.
A rule introduced this year requiring a 97 percent reduction in the sulfur content of highway diesel fuel phases in Sunday to an estimated 80 percent of the fuel sold in the United States.
The overall result is "the single greatest achievement in clean fuel since lead was removed from gasoline more than 25 years ago," says US Environmental Protection Agency chief Stephen Johnson.
"Diesel vehicles have always been 20 to 40 percent more energy efficient than comparable gasoline engines," said Allen Schaeffer, executive director of the Diesel Technology Forum, an industry group.
"With the switch to cleaner fuel, consumers will see more fuel-efficient diesel cars, pick-ups and SUVs (sport utility vehicles) on showroom floors in the years to come."