Trucks and SUVs led the gains, fueled by significant discounts on many models and low gas prices.
Several jubilant automakers celebrated their best October sales in years.
Toyota reported its "best-ever October" with sales exceeding 200,000 units, while Fiat-Chrysler touted its best October sales since 2001, with an increase of 15 percent. Audi also achieved its best-ever October sales results, with demand for Audi SUVs increasing 31 percent for the month.
GM said sales rose 16 percent in October compared with sales a year ago. Chevrolet turned in its best October results in 11 years, while the Chevrolet Silverado and Colorado pickups turned in their best October sales since 2006. Cadillac SRX sales were up 65 percent and Escalade sales rose 47 percent.
Nissan said its double-digit October sales increase was led by its light trucks, including a "stellar month" for the Nissan Rogue SUV, with a sales leap of 70 percent. Overall Nissan Group sales jumped 13 percent in October.
"October was a huge month for the industry, smashing expectations and continuing its hot streak," said Bill Fay, group vice president and general manager for Toyota Division, in a statement. "Toyota Division posted best-ever sales for the month led by October record-breaking sales of Highlander and RAV4."
Many automakers acknowledged the seemingly insatiable appetite for trucks and SUVs.
"The redesign of our full-size trucks and SUVs and our move into the small crossover and midsize pickup segments were smart bets, and our timing couldn't be better with industry sales at record levels," said Kurt McNeil, GM's U.S. vice president of sales operations, in a statement.
Ford's SUV sales were up 12 percent for the best October since 2004 and the Dearborn automaker reported that gains in its truck business were "especially strong, with F-Series delivering its fourth straight month of sales gains and its best October retail levels since 2004."
Jeep brand sales increased 33 percent. Fiat-Chrysler reported healthy sales of the Dodge Journey, Jeep Cherokee, Jeep Compass, Jeep Wrangler and Ram ProMaster. The Jeep Patriot recorded a 56-percent sales increase, the largest sales gain of any Fiat-Chrysler U.S. vehicle in October.
Edmunds says: Car shoppers searching for bargains will likely see discounts on cars and luxury vehicles as the year comes to an end and buyers continue to gravitate toward trucks and SUVs.