Several of the top automakers in the U.S. blamed rough October sales numbers in part on two fewer selling days compared to the same month last year.
Five of largest companies in the U.S. market reported sales declines over that span, including drops that ranged from just less than 2 percent for General Motors to 10 percent for Fiat Chrysler.
GM attributed its decline to rental sales and said that sales to retail customers actually increased. Chevrolet, GM's largest brand, saw slightly lower sales, while GMC and Cadillac fell by 6 percent and 9 percent, respectively. Buick sales increased by 7 percent.
"Based on initial estimates, GM outperformed the entire U.S. retail industry by a wide margin," the company said in a statement.
FCA, meanwhile, reported declines by every brand except for Ram trucks. Its flagship Chrysler brand slid by 45 percent alone.
Ford, the third of Detroit's "Big Three" automakers, plans to report its October totals later in the week following a fire at its headquarters.
Among overseas automakers, Nissan and Honda each said that sales of larger vehicles — bolstered by lower gas prices in the U.S. — kept their sales declines at about 2 percent and 4 percent, respectively.
Toyota sales, meanwhile, declined by nearly 9 percent.
Those six automakers accounted for more than 75 percent of the U.S. auto market in September, according to The Wall Street Journal.
In addition, Volkswagen reported a 19 percent decline in U.S. sales last month compared to the previous October — which was the first full month after its diesel emissions scandal was publicly disclosed by federal regulators.