The house commerce subcommittee on oversight and investigations will look into the roles of the U.S. Department of Energy and Exxon in last summer's gasoline shortage in the Washington area.

The investigation was requested by Rep. Herbert E. Harris II (D-Va.), who said yesterday, "We're now fooling around again with shortages and lines at some stations, and DOE still doesn't know, or doesn't want anyone to know, what caused the problem the last time."

Both DOE and Exxon, which is the largest supplier of gasoline in the metropolitan area, sent letters to Harris this week in answer to earlier charges by the Northern Virginia congressman that DOE was covering up statistics that showed Exxon was largely to blame for last summer's crisis.

If there is one thing on which DOE, Exxon and Harris agree, it is that part of the problem has to do with numbers.

"It's a matter of apples and oranges," Harris said as he looked at letters from Exxon's eastern region manager, R. E. Wilhelm, and DOE Deputy Secretary John C. Sawhill. "I'm still getting figures the way they want to give them to me," Harris said.

The congressman charged in a press conference on Oct. 18 that Exxon had shorted the Wshington area by 34 percent in June over the same month in 1978, and by 20 percent in July but that DOE was refusing to make those figures public.

Wilhelm's letter said "the reduction in the level of our deliveries was not nearly as great as the percentages you quoted." The Exxon official said "actual deliveries" to service stations in the District in those two months were down 15 and 10 percent respectively.

Sawhill's letter to Harris said Exxon's deliveries to two gasoline storage terminals in Northern Virginia -- which suppy 85 percent of all the gasoline, regardless of brand, to stations in the area -- were off 28 percent in June and 20 percent in July. "The difference between the figure quoted in your letter for Exxon's June deliveries -- 34 percent versus 28 percent -- represents trucked deliveries to Fairfax which supplemented deliveries for Exxon," Sawhill wrote.

Harris interpreted Sawhill's figures as confirmation of his earlier statement. He said "I'm still getting figures the way the (DOE and Exxon) want to give them to me." He said Exxon's figures, shown in gallons delivered, were for stations in the District of Columbia only, while DOE's statistics were in percentages, for fuel delivered to the terminals.

An Exxon spokesman insisted that the figures it reported for the city "would not change appreciably" if they had been for the entire area. He said Exxon "has documents that can be produced that will substantiate these figures" and the company would make them available to congressional investigators if asked.

"We meticulously lived up to the DOE allocation regulations," the Exxon spokesman said. "There was a shortage in the Washington area because of the way the DOE regulations worked, and it's unfair for the congressman to criticize us for following DOE's policies."

Asked why he thought an oil company would deliberately give the Washington area less than its fair share of gasoline, as he has suggested was the case, Harris said, "If I wanted to get major publicity to justify a massive increase in price, I would have caused shortages where they did."

Harris said "the first time they did it to us is their fault, but the second time it will be our fault for not stopping them."