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 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 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.

Toyota’s Scion brand scored the worst of the 33 car brands.