Korean cars are the top quality vehicles by a growing stretch, according to the 2015 JD Power and Associates Initial Quality Study, the most closely watched gauge of quality in auto manufacturing.
Japanese brands, on the other hand, are slipping down the rankings table, falling below the industry average for the first time in 29 years.
The twin South Korean brands, Kia and Hyundai, have moved to the top of the list.
USA Today reports the Kia brand ranked second behind the top brand, Porsche, which took first for the third year in a row. And the Hyundai brand moved up to fourth place, right behind third-place Jaguar.
Both Kia and Hyundai are owned by the same company, Hyundai.
Dip in fortunes for Japan
The latest rankings represent a turnabout from the many years in which Japanese brands have dominated the listing.
The highest-rated Japanese brand is now Nissan's Infiniti in fifth place, up from below average last year.
America's big three makers fared generally well. Chevrolet placed highest among traditional US brands at seventh, followed by Ford's Lincoln in eighth.
Both were ahead of Lexus and Toyota, which placed ninth and 10th. Ford has now climbed back above average after falling near the bottom two years ago.
The index is based on responses from 84,000 drivers who have bought or leased a 2015 car or truck model. It is based on defects or problems in the first 90 days of ownership.