• by Karl Greenberg , September 1, 2010

Sales of new cars and trucks in August reflect as much the short-term strength of the government's Cash-for-Clunkers program last year as consumer interest now. It is a difficult market to gauge because automakers showing sales declines last month are vying against their own successes with the program.

General Motors, for example, reports that its August sales of Chevrolet, Buick, GMC and Cadillac vehicles fell by a combined 11% to 184,921 units versus last August. Its three smaller brands -- Buick, GMC and Cadillac -- had sales gains, but Chevrolet fell, partly because it was Chevy that benefited from the program last year, which was focused on the non-luxury region of the new-auto market.

The automaker says Chevrolet had a total sales decline of 22% compared to last year, while retail sales were down 31%. By contrast, combined sales for Buick, GMC and Cadillac were up 37% for the month, compared to a year ago. Buick sales increased 66%. Cadillac sales in August were 83% higher than last year, per GM. GMC total sales were up 12% during the month.

The company says sales of full-size pickups were up 4% during the month, and full-size SUV sales were up 7%.

Jeff Schuster, executive director of global forecasting at J.D. Power and Associates, says GM's smaller brands are also benefiting from having vehicles in their lineups that people want -- smaller cars and crossovers -- and from the fact that since the brands have small portfolios, one fresh model or a couple can have a much more dramatic impact on overall sales.

"[Buick's] lineup wasn't as strong a year ago when they really had no smaller vehicles. The brand is much stronger with Regal and Lacrosse; the brand's image is shifting and vehicle style design and performance is helping that," he says.

For Chrysler, August is the fifth consecutive month of year-over-year sales increases. The company says 14 of its vehicles saw sales improvements. Its Jeep, Dodge and Ram brands posted year-over-year sales increases, helping the company post a 7% increase compared with sales in August 2009. Chrysler says August is the fifth consecutive month of year-over-year sales increases. August sales also were up 7% over sales in July, per the company.

Chrysler Group says it is the only major auto manufacturer to post a year-over-year sales increase in August. "I think so far, I would agree that the performance of Chrysler has surprised us a bit; [Chrysler Group] has been stronger than we had expected," says Schuster. "The new Grand Cherokee is helping, in fact, much of the Jeep lineup which looks strong."

The Auburn Hills, Mich.-based automaker is launching 16 new or refreshed vehicles this year, including a new Wrangler and all-new 2011 Dodge Durango SUV, based on the same platform as the new Jeep Grand Cherokee crossover. Jeep posted a 17% year-over-year increase in August.

Ram Truck Brand posted a 5% sales increase in August, compared with the same month in 2009, and Dodge posted an 8% sales increase in August. The company says Dodge Challenger sales were up 190%, compared with the same month in 2009.

In Dearborn, meanwhile, sales of Ford, Lincoln and Mercury brands were down 11% in August versus a year ago -- although year-to-date, Ford sales totaled 1.28 million, up 18%. J.D. Power and Associates reports that a stall in new-vehicle retail sales late in the month pulled sales for all players down for the month.