General Motors Co. brands made a big jump in the rankings of the 2013 J.D. Power Initial Quality Study, which examines the problems drivers encounter during the first 90 days of owning a new vehicle.

Porsche topped the list — it regularly ranks near the top — but the GMC truck division of GM was second, up from 12th last year. GMC was followed by Lexus, Infiniti and GM’s Chevrolet division.

Including Buick and Cadillac, all four GM brands scored above the industry average. It was the best showing for an American automaker. Ford and the Chrysler Group brands of Jeep and Dodge all scored below average in the study, which J.D. Power released Wednesday.

"GM quality has been improving over several years, but we weren't anticipating that GMC would be No. 2 and Chevrolet No. 5," said David Sargent, vice president of global automotive at J.D. Power. "That was higher than even GM anticipated. They were more than pleased with the results."

Acura, Toyota, Honda, Jaguar — which previously has finished near the bottom — and Hyundai rounded out the top 10.

The study measures the problems per 100 vehicles owners of the car experience.

Porsche had just 80. The industry average was 113.

Toyota’s Scion brand scored the worst of the 33 car brands with 161 problems per 100 vehicles. The other bottom-finishers were 29th-place finisher Mini, followed by Nissan, Mitsubishi and Fiat.

Although the ratings only look at the first 90 days of ownership of a new car, they are important because they tend to uncover design flaws and operational issues rather than the mechanical defects that show up in studies that look at longer time periods.

“These are soft-quality issues. People are complaining that things are not intuitive, are too complicated, not well thought-through and overly difficult to use,” Sargent said. “These problems are not the cars breaking down.”

But when owners bring the cars back to the dealers to try to find a fix, there’s not much that can be done because the problems are inherent in the design of the vehicle, he said.

This rankles consumers more than a problem that can be easily corrected with one trip to the dealer and a replacement part. Owners get frustrated when they realize that they just spent $25,000 or $30,000 on a car with a problem that they will now be stuck with for years, Sargent said.

“The design problems also have much greater impact on the customer’s likelihood to recommend the vehicle,” Sargent said.

Consumer frustration over Ford Motor Co.’s MyFord Touch system of controls for music, navigation, climate control and other functions have hurt that automaker’s standings in the rankings. Ford finished 27th, below all of its American car brand rivals with the exception of Chrysler’s Ram trucks.

“The technology is pulling them down,” Sargent said.

It's not because the Ford system is getting worse but rather because the automaker is putting it into more of its vehicles. More consumers are exposed to the system and start complaining about in the J.D. Power surveys, Sargent said.

Ironically, that hurts Ford’s rating even though it is improving the technology, he said.

“The successful companies will be those automakers that find a way to give customers the technology they want while at the same time making it sufficiently intuitive so all customers find it easy to use,” Sargent said.

Besides ranking the brands, J.D. Power also identified the best-scoring models in each segment of the auto market.

Chevrolet received five of the 26 model awards, while Honda, Kia, Mazda and Porsche each won two.

The Chevrolet models receiving segment awards were the Avalanche, Camaro, Impala, Silverado heavy-duty truck and the Tahoe. Honda received awards for the Civic and CR-V; Kia for the Soul and Sportage; Mazda for the Mazda2 and MX-5 Miata; and Porsche for the Boxster and 911.

Also receiving segment awards were the Acura TL; Buick Encore; Cadillac Escalade; Chrysler Town & Country; Ford Mustang; GMC Sierra LD; Hyundai Genesis Sedan; Infiniti FX; Mercedes-Benz GLK-Class; Nissan Murano; Smart ForTwo; and Toyota Camry.

The Lexus LS ranked highest in the large luxury-car segment and with a score of just 59 problems per 100 vehicles. That was the lowest average problem level among all models in the study.