GM plummeted 45% from a year earlier. Ford sold 132,248 cars and trucks last month, down 32% from a year earlier. Toyota outsold Ford on its way to a 23% decline. Volkswagen said its VW brand dropped 7.9%. Mercedes-Benz was down 34%, and Porsche plummeted 50%.
The results so far reinforce the projections of analysts, who had said the global credit crisis and plunging consumer confidence would contribute to the industry's 12th-straight monthly decline and the second-straight monthly year-to-year drop of more than 25%.
"This is the toughest economy we've seen in a long time," Mark Barnes, chief operating officer of VW Group of America, said in a statement.
Ford's U.S. brands -- Ford, Lincoln and Mercury -- fell 29.2%. Its Volvo unit plunged 52.1%. Ford's comparisons factor in 5,267 Jaguars and Land Rovers from October 2007; the U.K. brands are now owned by India's Tata Motors.
Ford sales analyst George Pipas had projected an industrywide October decline of 20% to 30%. He and some analysts had also forecast sales at a seasonally adjusted annual rate of 11 million. That would be the lowest since March 1983, according to the U.S. Commerce Department.
U.S. auto sales averaged 16.8 million this decade through 2007.
By September 2008, U.S. volume was off 12.8% from a year earlier. Of the four biggest automakers in the U.S., only two had reported monthly sales increases: GM in January and Toyota in April. Ford's last increase was in November 2007.
Chrysler has posted one monthly gain under its current owner, Cerberus Capital Management, in December. Analysts project it will report its third-straight monthly decline of more than 30% as Cerberus continues its effort to sell Chrysler.