DETROIT — It’s been a chilly autumn for U.S. auto sales.

Sales of new cars and trucks fell an estimated 4 percent in October as consumer demand waned, according to Autodata Corp.

Hyundai and Subaru both reported 4 percent sales increases from last October. But General Motors’ sales fell 2 percent, Toyota’s sales were down 9 percent and Fiat Chrysler’s sales dropped 10 percent. Honda’s sales fell 4 percent and Nissan’s were down 2 percent. Volkswagen’s sales fell 18.5 percent.

Ford Motor Co. said its sales figures would be delayed until later in the week because of an electrical fire at its headquarters that stopped dealers from reporting sales. Autodata estimated Ford’s sales fell 2 percent.

U.S. auto sales remain near their all-time highs, but after six years of growth following the Great Recession, they’re tapering off. October was the fifth month of year-over-year sales declines in 2016, a sign this year could fall short of last year’s U.S. record of 17.5 million sales.

“The fact that retail sales are beginning to contract despite high incentives and extremely low interest rates and gas prices is a clear indicator that this cycle has reached its peak,” said John Humphrey, senior vice president of J.D. Power’s global automotive practice.

Sales fell even though automakers increased average discounts per vehicle by 12 percent to $3,726 per vehicle, according to J.D. Power. But the average sales price still was expected to set an October record at $31,383. Prices are rising because more trucks and SUVs are being sold.

Incentives can draw buyers in the short term, but they can be dangerous for the industry, since they lower profits and hurt vehicles’ resale values. Kelley Blue Book senior analyst Alec Gutierrez said incentives are growing faster than average prices; if that trend continues, or if prices stagnate but incentives keep growing, there could be trouble for manufacturers.

“We’re on the upper end of the spectrum in terms of where we would feel comfortable,” he said.

Gutierrez and others say they expect automakers to cut production in coming weeks. Ford cut production at four North American plants in October.

Automaker reports for October:

General Motors Co. said its U.S. sales fell 1.7 percent to 259,000. All brands but Buick reported declines. Sales of its top-selling Chevrolet Silverado pickup fell nearly 4 percent, but Chevrolet Tahoe SUV sales rose 81 percent, while GMC Acadia SUV sales were up 24 percent.

 Toyota Motor Corp.’s sales fell 8.7 percent. Toyota brand sales were down 9 percent, while luxury Lexus sales fell 6 percent. Sales of the Tacoma small pickup rose 4 percent and Lexus SUV sales jumped 6 percent. But car sales tumbled.

 Fiat Chrysler Automobiles said its sales fell 10 percent.

 Honda Motor Co.’s sales fell 4.2 percent. Sales of the Honda HR-V small SUV jumped 46.5 percent, while sales of the luxury Acura MDX SUV were up 15 percent. But car sales dropped.

 Nissan Motor Co.’s sales fell 2.2 percent. Sales of the newly redesigned Nissan Armada SUV jumped 79 percent, while sales of the Murano SUV doubled from last year. But Infiniti luxury sales were flat.

 Hyundai Motor Co.’s sales were up 4.1 percent. The Tucson SUV saw an 11-percent increase.

 Subaru brand sales rose 4.1 percent on strong sales of the Outback SUV and the Crosstrek wagon.