DETROIT - Detroit's automakers continued to narrow the quality gap with foreign rivals, according to the 2008 Initial Quality Study by J.D. Power and Associates, the trusted report that measures defects and design problems within the first 90 days of ownership.

Consumers reported an average of 1.18 problems per vehicle in this year's study, and quality has improved so much across the board that the differences between brands are so small that they now are measured in the tenths and hundredths of problem per vehicle.

For example, the difference between Toyota, the highest-ranked mainstream brand, and Ford, now is eight-hundredths of a problem per vehicle.

"We're splitting hairs,'' said Dave Sargent, vice president of automotive research at J.D. Power and Associates. While he was reluctant to call the difference a tie, he said: "They're very close.''

Among Detroit's automakers, Ford Motor Co. turned in the strongest performance in this year's new-car quality study, with several notable accomplishments. General Motors Corp. performed respectably but showed room for further improvement. Meanwhile, Chrysler posted needed gains but still found itself trailing much of the industry.

Ford, which has been making significant quality strides in recent years, continued to rake in the accomplishments.

Its Mercury brand was the top-performing domestic brand in the study, with 1.09 problems per vehicle. That placed Mercury right between Toyota with 1.04 and Honda with 1.10.

The company's volume Ford brand improved for the fifth straight year and now is hot on the heels of Honda, with 1.12 problems per vehicle. That is just two-hundredths of a problem more per vehicle.

Ford also had 10 vehicles ranked in the model-segment awards, with three first-place winners. That included the Lincoln Navigator, the Ford E-Series van and the Mazda MX-5 Miata. Ford Motor Co. owns a controlling stake in Mazda.

Across town, GM had plenty of good news, too.

Six of GM's eight brands improved in this year's studies, and half ranked above average. That included Cadillac, Chevrolet, Pontiac and Buick.

Ten GM vehicles ranked in the model-segment awards. And while GM, like Ford, took three first-place awards, they were in critical categories.

The Chevrolet Malibu, which launched in the fall, took the top spot in the highly-competitive midsize car category. The Chevrolet Silverado LD was the top-ranked large pickup, and the Pontiac Grand Prix sedan was the highest ranked large car.

Meanwhile, Chrysler continued to improve but generally trailed much of the industry.

Dodge showed the most improvement and even had two segment winners, the Dodge Dakota midsize pickup and the Dodge Durango midsize SUV. Chrysler improved, too, and its PT Cruiser scored a second-place in the segment awards.

However, Jeep's performance slipped. That left it dead last in the initial quality rankings, with 1.67 problems per vehicle.

But to keep that in perspective, consider this: Jeep's performance is just half a problem more per vehicle than the industry average.

"Chrysler has gone through a very difficult period. They are launching a lot of new vehicles. Launches are problematic. Chrysler is not immune to that,'' Sargent said. "Chrysler has some way to go.''

Overall, luxury brands were the leader in this year's new-car quality survey.

Customers of Porsche reported less than a single problem per vehicle, 0.87, making that brand No. 1 in the survey, as it was last year.

Infiniti climbed to the No. 2 spot, with 0.98 of a problem per vehicle. And Lexus slipped to the No. 3 spot, with 0.99 of a problem per vehicle.

Mercedes-Benz took the No. 4 spot. That German brand also earned the distinction of best plant in the world. Its factory in Sindelfingen, Germany - which builds the CL-Class, the CLS-Class, E-Class and S-Class - had just 33 defects per 100 vehicles.