"We want to be known for great products, not great incentives," McNeil said.
But some analysts think GM will be forced to offer more deals in December to clear out higher-than-forecast inventory.
Asian brands also got a boost from some unusually big discounts, said Jesse Toprak, senior analyst for automotive pricing site TrueCar.com. TrueCar estimated that Hyundai and Kia, which were admonished by the U.S. government in late October for overstating gas mileage, increased incentive spending by nearly 30 percent. Nissan spending was up 45 percent to $4,273 per vehicle, by far the highest incentives in the industry.
Toyota said its 17 percent sales increase was partly because of post-Sandy demand. Honda was up 39 percent thanks to strong sales of the new Accord sedan and clearance deals on the outgoing Civic, which was replaced by a new 2013 Civic at the end of the month.
Luxury cars saw their usual year-end surge as holiday commercials started crowding the airwaves. Porsche's sales rose 71 percent to 3,865, a record month for the automaker. Infiniti, Acura, BMW and Lexus all reported big gains.
Edmunds.com analyst Jessica Caldwell said luxury brands have historically targeted their customers at this time of year because of holiday bonuses. That's no longer a driving factor, she said, but it's still a good time of year for people to buy 2012 model-year luxury vehicles because dealers are trying to clear them out.
Other automakers reporting sales Monday:
• Chrysler's sales were up 14 percent. Ram pickups were up 23 percent, while sales of the Fiat 500 minicar more than doubled.
• Hyundai's sales rose 8 percent, led by the Sonata midsize car and the Elantra compact.
• Volkswagen's sales rose 29 percent on the strength of the Passat sedan, which was up 75 percent.• Nissan's sales climbed 13 percent as sales of its new Pathfinder SUV more than tripled over last year.