Porsche Cars North America retains its top spot in this year’s J.D. Power and Associates 2007 Initial Quality Study, but Ford Motor Co. is the big winner as five of its vehicles grab top model segment awards.

The IQS, now in its 21st year, ranks vehicles based on the number of design and defect problems buyers have within the first 90 days of ownership. The study measured responses from more than 97,000 buyers or lessees of ’07 model vehicles between November 2006 and January 2007.

Lincoln led the charge for Ford, jumping from No. 12 in the IQS 2006 study, when it averaged 121 problems per 100 vehicles, to third this year, improving to 100 problems per 100 vehicles.

Both the Lincoln MKZ, an entry premium car, and the Lincoln Mark LT, a large premium multi-activity vehicle, led their segments. Other Ford vehicles to win are the Ford Mustang in the sporty mid-size segment and the Mercury Milan in the mid-size car segment. Ford-controlled Mazda Motor Corp. placed its MX-5 Miata atop the compact sporty car segment.

DaimlerChrysler AG’s Mercedes-Benz Car Group also won big, improving from No.25 to fifth place on the IQS, whose results were released today.

The new MKZ, along with the redesigned Honda CR-V and MercedesS-Class, which also won their segments, are notable because new vehicles or redesigns typically do not fare well in the study, says Neal Oddes, J.D. Power’s director-product research and analysis.

Meanwhile, the industry’s showing on the IQS remained flat, averaging 125 problems per 100 vehicles, up slightly from last year’s 124 problems. The average is significantly worse than two years ago, when it was 118 problems per 100 vehicles.

“All-new redesigns are still problematic for the industry,” Oddes says. “Integrating new technology is still difficult.”

According to the study, 48% of the problems are design-related, even though only 22% of the 228-questions focus on design.

“Design problems can be more severe,” Oddes says. “Defects are easier to fix.”

Ford’s improvement was due to “some excellent launches,” Oddes says. “The most improvement for Ford was on the defect side, because it was able to make changes at the manufacturing facilities.”

Toyota Motor Corp.’s Lexus Div. finished second overall – the same as last year – while Toyota dropped from fourth to seventh place.

Although Ford’s Land Rover division came in last, it actually improved the most, reducing the average problems per 100 vehicles from 204 to 170.

In what is likely bittersweet news for Ford, its Wixom, MI, plant, which built the Lincoln Town Car until it closed this month, won the Platinum award for the best plant.

Toyota’s Kyushu plant in Japan, which builds several Lexus models and the Toyota Highlander, won gold for the Asia/Pacific region.

Meanwhile, BMW AG’s Regensburg, Germany, plant, which makes the 3-Series Coupe and Sedan, won gold for the European region.

cbanks@wardsauto.com