Sales of American-Made Vehicles Plunge 20.4% : Autos: Light truck sales, which are sensitive to higher gas prices, plummet 28.5% in late November.

Sales of domestically built cars and light trucks plummeted 20.4% in late November, reflecting a continued slump in the auto industry and sagging consumer confidence, auto makers and analysts said Tuesday.

Particularly hard hit were sales of light trucks, which dropped 28.5% in the Nov. 21-30 period compared to the same time last year. Trucks, including pickups, minivans and sport-utility vehicles, aren’t as fuel efficient as cars and are more vulnerable to rising oil and gasoline prices.

Car sales during the period dropped 15.2%.

The 10 major U.S. auto makers reported selling an average of 29,510 cars and trucks a day during the period this year, compared to a daily rate of 37,062 during the same time last year.

“It’s at a 5.3-million annual rate, which is the weakest 10-day period that I can find since October, 1982,” said auto analyst David Healy of the investment banker Barclays de Zoete Wedd in New York. “It’s the first weak period since the Iraqi invasion of Kuwait, so it looks as though the big drop in consumer confidence and the looming recession are finally having an effect.

“Until now, sales were holding up pretty well,” Healy said. “My guess is they won’t stay that low, but it is kind of a warning shot.”

For the month of November, with imports from major overseas auto makers included, combined car and truck sales were 4.3% behind last year’s pace. Car sales fell 1.5% and truck sales were off 9.6%.

The Big Three auto makers--General Motors Corp., Ford Motor Co. and Chrysler Corp.--held 68.3% of the market for the month.

“Both the home builders and the automobile industry seem to be well into the recession with the rest of the economy just starting,” Healy said. “Our (economic) guru thinks it’s going to be a steep one, but it will be over by midyear 1991.”

The auto industry, preparing for a softening economy, has cut production schedules for the rest of the year.

GM Chairman Robert C. Stempel said last week that he expects that the giant auto maker’s fourth-quarter earnings will decline significantly from the third quarter, when the company earned $109 million excluding a $2.1-billion one-time loss for closing plants.

Through the first 11 months of this year, total car and truck sales in the United States stood at 13,151,749, down 4.9% from the same time last year.

The industry’s slump began in the third quarter of last year and generally, sales rates for 10-day periods have been lower than year-ago periods.

Ford suffered the most of the Big Three in this year’s late-November reporting period for North American-made cars and light trucks. Auto makers report sales of imported vehicles only on a monthly basis.

Ford’s combined sales of North American-made cars and trucks for late November were down 30.1% compared to last year.

Company sales analyst Joel Pitcoff said part of the downturn stemmed from fewer fleet orders from rental car companies, law enforcement agencies, taxi companies and big corporations.

“But throughout the month, we saw a progressive decline in retail traffic,” Pitcoff added.

“The accumulated bad economic news and uncertainty finally seems to be taking its toll on the retail market,” he said. “I think we can expect some fairly grim numbers to look at for the industry in the near future. And to top it all off, we never do well competing with Santa Claus.”

Through November of this year, Ford’s cars and trucks were selling at a pace 7.7% slower than last year.

GM said its combined car and truck sales for late November fell 22.5%. Through the first 11 months of the year, sales of GM’s North American-made cars and light trucks were down 4.1%.

Chrysler, which has suffered the most in this year’s sales downturn, said its late-November car and truck sales were off 17.4%. Through November of this year, the company’s combined car and truck sales were down 13.6% from last year.

Times researcher Amy Harmon in Detroit contributed to this story.

VEHICLE SALES

Nov.21-30 % change 1990 year to year GM* 94,111 -22.5 Ford* 59,438 -30.1 Chrysler* 41,545 -17.4 Honda U.S. 19,529 +25.0 Isuzu U.S.* 1,694 ** Mazda U.S.* 2,176 +35.3 Mitsubishi U.S. 1,323 -0.8 Nissan U.S.* 6,582 -43.0 Subaru U.S. 1,443 ** Toyota U.S. 8,238 -14.0 TOTAL 236,079 -20.4

*Includes light truck sales.

**No comparison possible.

There were 8 selling days in the selling period this year and last year.