The changeover to high-mpg models, in all segments, is the key market driver this year. Dealers say it has been the release valve on pent-up demand as fuel prices soared.
"Fuel efficiency continues to be a top purchaser driver," said Ken Czubay, Ford's U.S. sales boss.
Total U.S. vehicle stocks have been falling all year, down to a 52-day supply on June 1, from 66 days on Feb. 1. But car stocks are even tighter: 43 days on June 1, down from 60 five months earlier. Toyota and Kia started June with only enough cars to last 25 days; Hyundai had just a 22-day supply.
Dealers can sell new models with advanced fuel efficiency at or near sticker, while outgoing models require hefty incentives.
For example, the redesigned 2013 Malibu Eco with 37 mpg highway -- a mild hybrid that was introduced before the gasoline-engine versions -- has only a GM incentive of 2.9 percent financing for 60 months, and is the only model not eligible for a $1,000 cash discount for Saturn owners. But outgoing 2012 Malibus have a factory incentive of $4,000, or a combination of cash and 0 percent financing. Even GM employee discounts are lower on the 2013 Malibu.
"We just don't have to discount the new Malibu," said salesman Mike Blake at Wally Edgar Chevrolet in Lake Orion, Mich.
Sure, buyers always crave the latest model, but it's different this time. Not only is the sheet metal fresh; fuel economy is significantly improved.
For example, though it hasn't yet been EPA-certified, Ford projects that the 2013 Fusion with a 1.6-liter EcoBoost engine will get 37 mpg highway, compared with 33 mpg for the 2012 Fusion powered by a 2.5-liter naturally aspirated four-cylinder engine.
The four brands with redesigned mid-sized cars already on the market are scrambling to make more cars.
-- Volkswagen is adding a third shift at its Chattanooga plant to boost capacity to 180,000 Passats a year from 150,000. In May, VW Group of America CEO Jonathan Browning said VW has calculated the cost of expanding to 250,000 a year.
-- Kia's West Point, Ga., plant, which builds the Optima, is working overtime.
-- The Montgomery, Ala., plant, where Hyundai builds the Sonata, will stay on daily and Saturday overtime until it adds a third shift in September, "and then we'll see," a spokesman said. Hyundai Motor America CEO John Krafcik has said the brand's sales growth this year will be limited by capacity.
-- Toyota has scheduled daily and Saturday overtime at most North American plants through summer.
Camry sales are up 44 percent through May -- and, yes, more supply after last year's Japan earthquake has a lot to do with it. But so does improved fuel economy on the redesigned version that arrived last fall. The 2012 four-cylinder gets 25 mpg in the city and 35 on the highway, compared with 22/32 for the model it replaced. Said Toyota Division General Manager Bob Carter: "A large percentage of the increase is the consumer response to the new car."
Bradford Wernle and Mark Rechtin contributed to this report