Industry Study Questions Shift to ‘Clean’ Fuel : Environment: The report says the requirements of the Clean Air Act may not result in reduced smog.

A study by the automobile and oil industries issued Wednesday calls into question two key requirements of the new Clean Air Act regarding the composition of gasolines intended to reduce smog.

Results of the study were released as the federal Environmental Protection Agency pressed ahead with proposed rules that would implement the law’s requirements for cleaner-burning gasolines in the nation’s nine most-polluted cities, including Los Angeles and San Diego.

The study’s results are sure to intensify the debate over the rules, which would dramatically change the makeup of gasoline, the way it is refined and marketed and the resulting costs that would eventually find their way to the corner gas pump.

Specifically, the industry study concluded that two chemical changes to gasoline--either reducing the level of chemicals called aromatics or increasing the level of oxygen--would have little effect on the formation of ozone, the main component of smog.

The conclusions directly challenge specific requirements in the Clean Air Act, passed last year, particularly the oxygen requirement.

Federal and state air quality officials downplayed the significance of the study’s findings. “We don’t consider the results particularly surprising,” said Richard Wilson, director of the EPA’s office of mobile sources, which is overseeing the federal rule-making process.

Regulators said the results would be taken into consideration, along with other research, in formulating final rules.

The study is one of the largest of its kind and an example of unusual cooperation between two major industries, involving the Big Three U.S. auto makers and 14 oil companies. By its completion in 1993, it will have cost $40 million.

Starting in 1995, the Clean Air Act would limit at 1% the level of a specific aromatic chemical--cancer-causing benzene. It would also require the addition of at least 2% oxygen to gasoline--most likely in the form of methanol- or ethanol-based compounds--to promote more efficient burning.

In addition, the act requires that any new gasoline formula result in a 15% reduction in toxic emissions and a 15% reduction in emissions of smog-forming volatile organic compounds starting in 1995.

The requirements would mean changes to the nation’s oil refining and marketing system that the industry estimates would cost tens of billions of dollars. In particular, refiners are concerned about a possible shortage of capacity to make a key additive--methyl tertiary butyl ether or MTBE--which adds oxygen to gasoline.

The study “is causing, as you might expect, some degree of consternation on the part of some people who have to meet the government’s Clean Air Act requirements,” said Joseph M. Colucci, co-chairman of the Auto/Oil Air Quality Improvement Research Program, which conducted the industry study.

“They would conclude that just meeting them is not (meeting) the intent of the law, which is to reduce ozone in the cities in the summertime,” said Colucci, head of the fuels and lubricants department at General Motors Corp. The oil industry has opposed mandated formulas for gasoline, preferring emission reductions goals.

The study did find that altering other gasoline components resulted in lower ozone formation. Specifically, it concluded that reducing the level of sulfur and olefins would cut smog, as would lowering the boiling point of gasoline.

Regulators downplayed the findings. The EPA’s Wilson said the requirements to reduce benzene and increase oxygen levels were intended as much to reduce the emission of toxic chemicals as to cut the formation of smog.

Bill Sessa, a spokesman for the California Air Resources Board, challenged some of the assumptions of the study’s computer model. Sessa argued that the models--which made estimates of urban air quality in three cities in the years 2005 and 2010--minimized smog reductions that might occur before the turn of the century.

Meanwhile, the EPA on Tuesday proposed detailed guidelines for a federal program to introduce lower-emissions gasolines in the nation’s nine smoggiest cities. Those are: Los Angeles, San Diego, Baltimore, Chicago, Houston, Milwaukee, New York, Philadelphia and Hartford, Conn.