The changeover of General Motors' full-size pickups and unseasonably high sales a year ago led to an estimated 16 percent decline in its U.S. light-vehicle sales last month.
Chevrolet, according to estimates from the Automotive News Data Center, led the double-digit slide for GM in September. The bow-tie brand was down an estimated 18 percent from a year ago, when replacement demand following two major hurricanes inflated sales.
Most notably, the Chevrolet Silverado full-size pickup dropped an estimated 19 percent because of low inventories of popular crew-cab models as the company continues to roll out the next-generation pickup and cut its incentive spending. The Silverado's estimated sales of 44,962 vehicles were short of the 51,856 pickups sold by Fiat Chrysler Automobiles' Ram brand. Sales of the Silverado's sibling, the GMC Sierra, fell an estimated 35 percent.
Combined, the decline of the full-size pickups represented roughly 38 percent of GM's overall volume loss for the month, according to Automotive News Data Center estimates.
For the third quarter, GM reported that the Silverado was down 14 percent while the Sierra dropped 7.1 percent. For the year, the Silverado is up 1.4 percent while the Sierra is down 1.4 percent.
"We entered the quarter with very lean inventories of our 2018 model full-size pickups, so we focused on driving a very strong mix of SUVs, crossovers and mid-size pickups," Kurt McNeil, GM's U.S. vice president of sales operations, said in a statement.
GM reported overall sales for the quarter declined 11 percent, led by roughly 11 percent declines at Cadillac, Chevrolet and GMC. Buick, the automaker said, was down 7.3 percent.
GM's car sales in the third quarter were down 24 percent, while crossover sales dropped 9.2 percent and truck sales, including full-size SUVs and vans, slid 6 percent.
GM, which this year started reporting sales quarterly, said its sales for the first nine months of the year were down 1.2 percent to about 2.2 million vehicles.
Here's a look at Automotive News Data Center estimates for GM's September sales in the U.S.:
Brands: Buick down 11%, Cadillac down 17%, Chevrolet down 18%, GMC down 8.6%
2018 U.S. market share: 16.8% through Sept. vs. 17% through Sept. 2017.
Notable nameplates: Buick Encore down 20%, Buick Enclave up 16%, Cadillac XT5 down 29%, Cadillac CT6 down 31%, Chevrolet Silverado down 19%, Chevrolet Equinox up 13%, Chevrolet Traverse down 9.9%, Chevrolet Cruze down 26%, Chevrolet Volt up 28%, Chevrolet Corvette down 34%, GMC Acadia down 40%, GMC Sierra down 35%
Incentives: $4,716 per vehicle, down 9.6% from a year earlier, according to ALG
Average transaction price: $37,276, up 3.6% from a year earlier, according to ALG
Fleet mix: 21% in the third quarter
Inventory: 798,839 vehicles, down about 22,000 from a year ago
Quote: "Consumer confidence is high and rising, thanks to the robust job market, faster wage growth and the boost to take-home pay from tax reform," said GM chief economist Elaine Buckberg. "We believe 2018 will be the fourth year in a row with total industry sales above 17 million units."
Did you know? GM's average transaction price of $35,974 for the third quarter was a new record for the period, up roughly $700 from a year ago.