Lexus, Porsche top vehicle dependability rankings

Those problems are likely to grow as newer cars make their way into the three-year reliability study. In J.D. Power's study of quality after three months of ownership last year, owners reported more problems with audio, entertainment and navigation systems than with any other vehicle feature, Festekjian said.

This year's study found that the Toyota Prius was the most reliable small car and the Hyundai Sonata was the most reliable midsize car. The Toyota RAV4 was the highest-ranked small SUV and the Chevrolet Tahoe was the most reliable big SUV. The Lexus RX midsize SUV had the fewest problems of any vehicle, at 57 per 100.

Dependability rankings are important to car companies, since buyers who are happy with a purchase are more likely to stick with that brand in the future. J.D. Power said 54 percent of owners who do not experience any problems with their vehicle stay with the same brand for their next new vehicle. That slips to 41 percent when owners experience three or more problems.

Sargent said the results should give buyers more confidence in older vehicles, whether they're keeping their current model or shopping for a used car. But he says dependability keeps improving, so people who buy new cars this year can have even more confidence in their cars' performance three years from now.

The 2013 study, which was released Wednesday, was based on responses from more than 37,000 original owners of 2010 model-year vehicles after three years of ownership.