A Department of Commerce Study, the results of which are questioned by other Carter administrationn officials, has concluded that present automobile mileage standards will cost consumers " $2 billion inn excess of the value of gasoline savings" between 1980 and 1984.

The study, by Assistant Secretary for Policy Jerry Jasinowski, backs the automobile industry, which is seeking lower standards for those years on the way to meeting the 27.5-mile-per-gallon mark set by law for 1985.

Jasinowski's recommendations for lower standards were sent to the National Highway Traffic Safety Board, which is considering the auto industry's request for "straight-line" as opposed to the present "front-loaded" standards. As of now the industry is supposed to produce cars that average 24 mpg in 1982, and 26 mpg in 1983. Tr for add one

The difference in the two approaches add up to only "a slight fuel-saving benefit," the study said. Over the lifetime of cars produced from 1980 to 1984, "a total of approximately 7 billion gallons of gasoline would be saved" by the tighter standard.

"The front-loaded standards would save roughly 23 days of gasoline consumption over the 1981 to 1993 period," it continued. "This gasoline consumption savings is small compared to the large costs incurred to achieve front-loaded standards."

Joan Claybrook, director of the National Highway Traffic Safety Board, was sharply critical of the Commerce study. "They took the Ford and GM numbers, added them together and divided by "two" to get the cost of meeting the tighter standards, Claybrook said.

"We don't do it that way," she said. "We analyze the company numbers."

Claybrook said her agency was analyzing information from the companies in a number of different ways to make sure there are no omissions, what they have said in the past, and how the detailed plans for meeting the standards tie in with the characteristics of the companies' present fleets.

"Commerce didn't do that," Claybrook declared.

The Commerce study agreed that meeting the tighter standards is technically feasible. "The issue is which technological path is both feasible and efficient for mass production in time to meet the mandated standards," it said.

"Under the current front-loaded standard," it continued, "costs are higher, engineering and marketing risks are greater, and the margin for errors of miscalculation that could cause adverse effects is smaller."

One potential benefit of the tighter standards is that they would reduce oil imports slightly and perhaps make world oil prices some tiny bit less than they otherwise would be. The Commerce study said that the trade benefits are not that clear, however, because reducing weight in cars will probably lead to higher aluminum imports as steel is replaced.

"The standards will induce aluminum purchases that contribute to inflationary pressures as well as to increased levels of imports," the study said.

"Based upon information submitted to the Department of Transportation by the industry and our own analyses, the front-loaded program does not appear to be economically practicable. It puts economic pressures on materials markets, heightens the financial risk to the industry, and threatens the competitive structure of the automobile sector," Jasinowski's report concluded.