Seven of the top 10 spots in Consumer Reports' annual reliability rankings went to Japanese brands.
Toyota Motor Co.'s Scion, Toyota and Lexus brands took the top three spots, while Mazda Subaru, Honda and Acura were close behind.
In sharp contrast, Ford Motor Company's reliability slipped. Two years ago, 90 percent of Fords rated average or better than average for reliability.
"But in the last couple years, they've released some new or redesigned models that have had more problems than normal," said Consumer Reports' Rik Paul.
Those include the Explorer, Fiesta and Focus. Ford's electronic infotainment system also has had problems.
The rankings, released Monday, predict the reliability of 2013 model-year vehicles based on surveys of Consumer Reports' readers.
This year, 800,000 people submitted information on 1.2 million vehicles from the 2010 to 2012 model years.
General Motors showed improvement. Cadillac was ranked the top U.S. brand, and its CTS Coupe was the most reliable domestic car.
The most reliable car overall was the subcompact hybrid Prius C.
All Priuses had above average reliability.
"When the Toyota Prius was released 12 years ago, there was a lot of skepticism about how well it would hold up," Paul said. "We're finding most hybrids and electric vehicles are proving very reliable."