GM's four brands averaged 98 problems per 100 vehicles, and it was the only automaker with fewer than one problem per new car, passing Toyota Motor Corp. and Honda Motor Co., which tied for second among automakers with 103 problems per 100 models surveyed.
Power said the Lexus LS sedan, which was redesigned for 2013, was the most trouble-free vehicle with 59 problems per 100 vehicles surveyed.
But it was the only Lexus model to top a segment. The brand grabbed the most awards each of the last four years and topped every segment that it competed in just seven years ago.
"They will consider this disappointing," Sargent said of Toyota and Honda. "Toyota would expect Lexus to be No. 1 and Toyota to be No. 2. That's their mission. Honda would expect to be in the top five. And they're not."
Ford Motor's Lincoln brand tied the industry average of 113 per 100 vehicles, but with 131 problems per 100, the Ford brand finished No. 27 of 33 ranked marques, the same position as last year.
The Ford C-Max was last among all models studied with 222 manufacturing glitches or design flaws per 100 vehicles, nearly twice the industry average of 113, USA Today reported. The five-passenger crossover is new for 2013 and only available as a hybrid or a plug-in hybrid.
All GM brands finished above industry average. In addition to No. 2 GMC and No. 5 Chevrolet, Cadillac tied for 13th and Buick tied for No. 15.
"Nothing energizes us more than receiving the verification of quality from our customers," Alicia Boler-Davis, head of global quality and U.S. customer experience for GM, said in a statement.
Porsche, with 80 problems reported per 100 vehicles, finished well ahead of its corporate stablemates, No. 13 Audi and No. 23 Volkswagen.
GMC and Chevrolet were the only nonluxury brands ranked in the top five.
The Acura and Toyota brands tied for No. 6, Honda was eighth and Jaguar ninth. Hyundai, Kia and Mercedes-Benz tied for No. 10.
Power redesigned the study for 2013, after seven years, for several reasons.
Questions about outdated hardware such as cassette players have been updated to include new features such as voice recognition and lane-departure warning.
Power also switched from paper questionnaires to asking randomly selected owners to respond online.
The changes allowed the market research firm to obtain more follow-up details from owners about any problems. The change was requested by automakers surveyed and who pay Power for analysis of the data. Automakers use the study to assess quality and to improve product quality and launches.