US automakers also placed three vehicles on the magazine's list of "top picks" for vehicles, the first time that's happened in 17 years. The rankings were unveiled Tuesday in the magazine's annual auto issue.
Buick placed seventh in the brand rankings. But the brand rankings and top picks still were dominated by Japanese and German manufacturers, with Lexus, Mazda, Toyota, Audi and Subaru taking the top five brand spots.
The magazine calculates each brand's overall score with a composite of its vehicles' road-test scores and reliability scores for each model in its annual survey of subscribers. It's the third year for the brand rankings.
Porsche placed just ahead of Buick at number six, while Honda, Kia and BMW rounded out the top 10 brands. Mercedes-Benz, Acura and Infiniti all suffered precipitous declines in their rankings due to unreliable new models or poor road test scores. Mercedes fell out of the top 10 to 21st, while Acura dropped from number two to 11 with an unimpressive test of the new RLX sedan, the magazine said.
In the model rankings, the top overall finisher was California-based Tesla's Model S electric car, for the second year in a row. The Model S, which cost the magazine $89,650, finished first due to its performance and technical innovations, the magazine said. Buick's Regal midsize car beat the BMW 328i as the top sports sedan, and the Chevrolet Impala was named the top large car.
The model rankings show Consumer Reports' favorite among the 270 vehicles its team has recently tested. The rankings are closely watched in the auto industry, since shoppers consistently cite Consumer Reports as a main source of car-buying advice.
Other top picks included the Subaru Impreza in the compact car category, Subaru Legacy in midsize cars, Toyota Prius as the best green car, Audi A6 luxury car, Subaru Forester small SUV, Toyota Highlander midsize SUV and the Honda Odyssey minivan.
Japanese vehicles won six of 10 top pick categories, but that was the smallest number in the 19-year history of Consumer Reports top picks.
"For years domestic automakers built lower-priced and lower-quality alternatives to imports, but those days are behind us," said Jake Fisher, the magazine's director of automotive testing.
But other U.S.-based automakers still had problems. Of 28 automotive brands included in the rankings, four of the bottom six finishers came from Detroit. The Chrysler brand finished 23rd, followed by Ford, Dodge, Mini, Jeep and Fiat. The bottom brands all had poor reliability and models with low road-test scores. Ford showed modest improvement as its infotainment systems had fewer reliability problems.
Consumer Reports buys vehicles anonymously and performs more than 50 tests on them, including evaluations of braking, handling and comfort. Top picks must be at or near the top of the rankings in performance, reliability and safety, the magazine says.
The AP contributed to this report.