Retail diesel surged 10.4 cents to $4.059 a gallon, the first time the national average price has crossed above $4, the Department of Energy reported. Also last week, both the U.S. gasoline average and crude oil prices set new records.

I want to know why diesel is so much more expensive than gasoline. Diesel is a byproduct of gasoline. It should be cheaper.

Nearly 90% of the biodiesel available for sale in the United States meets the established standards for quality, an improvement over past surveys but still an unacceptable situation for trucking, a new report by the Department of Energy said.

U.S. diesel prices remained at historically high levels last week, even though the official retail average dropped 0.9 cent to $3.955 a gallon, leading several trucking executives to express concern over the future of independent drivers and small fleets, and others to push for government action.

Clean Diesel Technologies said Tuesday it has licensed its wire mesh filter technology to Headway Machinery Co. Ltd., the largest commercial diesel engine exhaust company in China.

The U.S. Environmental Protection Agency said it is making available almost $50 million in grants to establish clean diesel projects aimed at reducing emissions from the nation’s existing fleet of diesel engines.