���ϳԹ���

RENTON, Wash. — In the struggle to squeeze a few more miles out of each tank of fuel, truck makers are designing tractors with the aid of computer models and wind tunnels more generally used to tweak race cars or airplanes.

ARLINGTON, Va. — A top Navistar Inc. official said the company is pursuing its own solution to meet the 2010 U.S. emission standards, because it doesn’t believe the fuel savings claimed by competitors will justify the higher costs and more complicated systems associated with the new engines.

California environmental regulators said last week the U.S. Environmental Protection Agency has granted the state a waiver that will allow enforcement of its regulation requiring emission-control retrofits on refrigerated trucks and trailers.

Paccar Inc.’s parts dealers are offering the company’s Engine Control Systems Purifilter, an aftermarket passively regenerating diesel particulate filter approved by the California Air Resources Board for installation and use in a wide variety of Class 8 trucks.

American Trucking Associations will exhaust all legal avenues to fight employee-only concession requirements contained in the Port of Los Angeles’ clean trucks plan, ATA President Bill Graves said.

Ultra-low-sulfur diesel, the standard fuel of heavy-duty trucking since late 2006, has more energy content than engineers originally had expected, a welcome surprise, according to a study from the American Transportation Research Institute.

A top U.S. Environmental Protection Agency official said last week that the agency has “absolutely no intention” of granting the request by truck and engine manufacturer Navistar Inc. for a two-year delay in implementing 2010 federal diesel emission standards for new heavy trucks.

U.S. Environmental Protection Agency Administrator-designate Lisa Jackson said she was “open to discussion” of a carbon tax to limit greenhouse gas emissions and would immediately begin a review of the Bush administration’s denial of California’s request to regulate those emissions from automobiles.

The Environmental Protection Agency, as proposed, has formally required new heavy trucks to have warning lights that indicate when engine emission controls are malfunctioning or deteriorating, starting in 2010.