Task Force Disputes Diesel Complaints

A task force looking into truckers’ complaints about the state’s new low-pollution diesel fuel has found that relatively few engine problems have resulted from the product--and that those that have are probably linked to refining methods, not the fuel standards themselves.

The trucking organization that helped persuade Gov. Pete Wilson to form the task force angrily condemned the findings released Wednesday. State regulators, who had been widely criticized after the diesel was introduced Oct. 1, claimed vindication.

“It underscores what we’ve been saying all along,” said Bill Sessa, a spokesman for the California Air Resources Board. The agency had mandated lower content of a diesel component called aromatics--a change that some truckers said caused widespread failure of their engines.

“The leaking O-rings”--devices used in various parts of diesel engines to prevent fuel leaks--”weren’t supposed to happen at all,” Sessa said. “But it happened to a small percentage of vehicles on the road, almost all of them high-mileage.”

The task force, he noted, accepted an ARB study of 7,000 heavy diesel trucks that found leaks from any source in engine O-rings in only 2.7% of the trucks.

“Frankly, that is pretty negligible,” said James J. Lee, spokesman for the California Environmental Protection Agency--particularly, he said, since most of the problems occurred with older O-rings likely to be replaced soon anyway.

Still, the report acknowledged that for the “relatively small percentage” of truckers affected, the problems were serious.

Dave Titus, spokesman for the California Trucking Assn., complained that the task force did not accept thousands of reports of engine failure that his organization presented. “We think this is an absolute government cover-up of a major screw-up,” he said.

Wednesday’s report found that the Oct. 1 changes in diesel fuel--which also included a federally mandated switch to lower sulfur content--may not be directly causing the few mechanical problems reported.

The culprit, the task force found, is more likely the process--called hydrotreating--that refiners use to lower diesel’s sulfur content. Hydrotreating, it said, could affect the lubricity of diesel and the ability of O-rings to swell and shrink.

A spokesman for Chevron Corp., the largest diesel refiner in the state, said the company already mixes in additives to restore lubricity.