New Diesel Rules Would Cut 90% of Vehicle Smog

WASHINGTON — The Clinton administration today will propose rules to eliminate 90% of the pollutants from the diesel smokestacks of 18-wheelers, heavy-duty construction trucks and passenger buses beginning in 2006.

The proposed regulations, regarded by some environmentalists as the toughest yet for big diesel-powered vehicles, contain two key components.

First, the rules would require petroleum refiners to cut 97% of the amount of sulfur now found in their diesel fuels. Sulfur fouls up catalytic converters and other equipment used to remove pollutants from vehicle exhaust.

The cleaner diesel fuel would begin flowing in the U.S. market in 2006, according to government and private sources, who provided written summaries of the plan developed by the Environmental Protection Agency.

Second, the rules would require new 18-wheeled cargo haulers to begin using catalytic converters and computerized pollution controls that have been used on passenger cars for 25 years.

Truck manufacturers would begin making changes to their vehicles in 2007. By 2010, all new heavy-duty trucks and passenger buses would have to meet the new clean-air standards under the EPA proposal.