Almost every automaker made significant strides in vehicle dependability in a new survey, but General Motors Corp. (GM), Ford Motor Co. (F) and Toyota Motor Co. (search) were among the top performers, J.D. Power and Associates said Wednesday.

The closely watched survey, which has been published since the late 1980s, measures dependability by questioning owners of three-year-old vehicles about problems they're experiencing, such as wind noise or excessive brake wear. This year's survey questioned 50,635 owners of 2002 model-year cars and trucks.

Chance Parker, executive director of product and research analysis at J.D. Power (search), said the industry showed a 12 percent improvement in this year's survey. The industry average was 237 problems per 100 vehicles this year, compared with 269 problems per 100 vehicles in 2004.

Parker said manufacturers fixed a wide variety of problems in the 2002 model year.

"Almost every manufacturer got better this year, and we don't always see that," Parker said. "Manufacturers have already picked all the low-hanging fruit, so now they have to tackle every little thing."

Lexus, Toyota's luxury nameplate, was the top-performing brand with 139 problems per 100 vehicles, while Kia was the worst performer with 397 problems. Hyundai Motor Co. (search) showed the most improvement, with 260 problems per vehicle compared with 375 problems in the 2001 model year.

Parker said Hyundai also improved dramatically when J.D. Power did its initial quality survey in 2002. That survey measures problems in new vehicles in the first 90 days of ownership.

"The 2002 initial quality survey is when we first saw a really big improvement from Hyundai, and that has translated into really high durability," Parker said. "This seems to validate the progress they've made."

GM had the winners in eight of 19 vehicle segments. The Chevrolet Prizm was the top-performing compact car, the Buick LeSabre was the top full-size car and the Chevrolet S-10 was the top mid-size pickup.

GM outstripped Ford, which had five segment winners, and Toyota, which had four. Parker said that ranking may surprise consumers, who perceive poor quality at GM because of vehicles the automaker made in the past.

"Once you as a manufacturer have a reputation, it's very difficult to change it," Parker said.

Parker said the appearance of the Toyota Prius on the list of the top performers could help sales of hybrid cars, since some consumers may have been wary about the long-term performance of those vehicles.

GM and Toyota also were the best performers in this year's initial quality survey, which was released last month.

Parker said the initial quality survey typically gets more attention because people are interested in new vehicles, but dependability is extremely important because good performers will have more loyal customers and lower warranty costs.

"We're always trying to make sure people understand that while dependability is not as sexy as the initial quality survey, at the end of the day it might be more important," Parker said.