The Environmental Protection Agency proposed new standards Tuesday to cut harmful emissions from automobiles operating in cold weather, saying the rules could reduce pollution levels 29% nationally.
Improving a car's cold-weather performance would also reduce pollution levels in regions with higher temperatures, such as Southern California, officials said.
Tightening the regulations for auto makers would affect 40% of all cars and trucks in the 1993 model year, increasing to all models by 1995 as the rules are phased in, officials said.
The new carbon monoxide standards would require improvement in engine calibrations to reduce unnecessary fuel enrichment, increasing average car prices by $19 to $31, officials said. But improved fuel economy resulting from more complete engine combustion would more than offset the increased purchase cost, they said.
EPA Administrator William K. Reilly said the new regulations not only would improve air quality but could save up to 43,000 barrels of oil each day due to more efficient fuel consumption.
Because concentrations of carbon monoxide increase significantly at colder temperatures, the agency said it planned to require automobile manufacturers to further improve engine calibrations so that emissions are greatly reduced in winter weather, particularly when cars start up.
The current federal pollution limit, which applies only to automobile performance in temperatures of 68 to 86 degrees, is 3.4 grams per mile. Beginning in 1993, the EPA wants many new cars to meet a standard of 10 grams per mile at a temperature of 20 degrees. The new standard for light trucks would range from 12 to 15 grams per mile, depending upon weight.
The cold-weather standards are more liberal than warm-weather rules because emissions are harder to control at lower temperatures, officials said. But they stressed that the proposed improvements would serve to reduce cold-weather emissions by more than one fourth.
Harmful automobile emissions result from incomplete combustion of fuel and are particularly high during the first few minutes after a vehicle is started.
EPA tests of recent-model vehicles show that emission levels are below the 3.4-grams-per-mile standard at a temperature of 75 degrees. But at 20 degrees, emissions range up to 35.9 grams per mile.
Fred Bowditch, vice president of the Motor Vehicle Manufacturers Assn., said his organization has been discussing the proposed standards with the EPA for six months.
"This is, in fact, a first draft, and there will be more discussions on the subject," Bowditch said. "But we're more or less prepared for the regulations. The numbers the EPA has proposed will be difficult, but we'll take them in stride one way or the other."
Under its rule-making procedures, the EPA is inviting public comment and will hold a hearing on its proposed standards before issuing final rules later this year.
"The standards being proposed are based on the levels of control the agency believes are technologically feasible and cost-effective in the near term," a spokesperson said. "To determine the amount and kind of vehicle control needed in the future, the agency is undertaking a long-term study to determine the need for further regulation."