DETROIT — When it comes to car quality, think Korean.

Hyundai Motor Co. leads in five categories in the annual vehicle-quality study released yesterday by Strategic Vision Inc., a San Diego-based market research company and consultant to automakers.

Hyundai's rise in the rankings is only the latest sign of the improved overall quality and declining number of defects in today's cars and trucks, said David Cole, chairman of the Center for Automotive Research in Ann Arbor.

"They're coming together to a point where the differences are almost meaningless," Cole said.

He said that means buyers will pay increasing attention to dealer service, new technology, fashion features, price and fuel economy.

Once known best as the maker of cheap, entry-level cars with nagging manufacturing flaws, the South Korean automaker outperformed its Japanese, European and U.S. rivals in this year's survey, based on interviews with 27,780 people who bought 2007 models in September-November 2006.

Last year, Hyundai had no winners. And highly regarded Toyota Motor Corp., despite improving its overall quality, went from four leaders last year to one in 2007.

"Even though Hyundai is often overlooked by the U.S. customer, Hyundai's success in 2007 is not surprising given its current products and ... leadership that is looking to the near and distant future with new designs from styling to powertrain," said Darrel Edwards, Strategic Vision's chief executive.

Hyundai's Azera led among large cars, and its Santa Fe led among small sport utility vehicles. Its Entourage was tied for best minivan with the Quest by Nissan Motor Co. and the Sedona by Hyundai affiliate Kia Motors Corp.

The Kia Sorento led among medium SUVs, Strategic Vision said.

BMW AG led in three individual categories plus best overall brand, and Nissan, Ford Motor Co. and DaimlerChrysler AG led in three each.

Strategic Visions asks buyers to rate all aspects of their new vehicles, from the purchase itself to the ownership and driving experience.

What's new this year is not who's first or second, but rather how satisfied buyers are in general, said company President Alexander Edwards.

"Everybody's doing a terrific job — that's the news," he said.

Based on a 1,000-point scale, the average new vehicle was rated 864, up from 861 in 2006 and 831 in 1998. As a result, he said, "cues of quality" rather than the number of defects "have a greater impact on the purchase decision."

Overall, Volkswagen AG had the highest corporate average, followed by Honda Motor Co., General Motors Corp., Toyota and Hyundai. Among brand names, BMW was followed by Infiniti, Mercedes Benz, Mini and Jaguar.