J.D. Power is raising the bar in its quest to verify auto industry quality.

In new private studies, it is setting out to measure durability, de pendability and how this relates to resale and residual values.

JDP is testing vehicles by putting 150,000 miles on them in one year to simulate four or five years of use. One example of what can go wrong? Seats and dashboards may be designed to last four or five years, but not, say, on the desert.

U.S. automakers typically “thrift” interior materials, so they don't hold up. Not so Mercedes or Lexus, for example.

JDP has four studies each year:

  • Initial Quality Study (IQS) released in May;

  • Customer Satisfaction with Dealer Service (CSI) due in this month;

  • APEAL (vehicle attributes) coming in September;

  • The Vehicle Dependability Study (VDI) covering used cars arriving in November. JDP also rates factory quality each year.

All JDP results show the Japanese are very much in command, with the Europeans closing the gap and the Americans dead last in studies and vehicle categories. But because the competition continues to improve, closing the gap between Japan and everyone else is tough.

“The Europeans are closing it faster than the Americans, but there are really small differences between the Europeans and Americans,” says Joseph Ivers, partner and executive director of JDP's quality and customer satisfaction research.

In the May IQS, which measures problems per 100 vehicles (PP100) during the first 90 days of ownership, Toyota Motor Corp. (including Lexus) came out on top among 54,000 owners and lessees surveyed, and the Japanese as a group led overall. The Europeans made big gains from the 2000 study, almost equaling the Japanese. U.S. automakers also showed improvement, though trailing by a considerable margin, study results show.

Mr. Ivers says it's tough to really pin down who's best because “within all three (Japanese, U.S., Europe) there are such huge variations between vehicles.”

But things ain't as bad as you'd think. “It was a good year for quality improvements at General Motors Corp. and DaimlerChrysler corp.,” Mr. Ivers says.

Based on JDP PP100 ratings, the Lexus 430 topped everyone with 58/100. Impala from 2000 to 2001 reduced its PP100 by 34 to 110, coming in fourth best in its segment. Jeep Wrangler cut 57 PP100 to finish second in its group. Saturn L also showed a big reduction, Saturn, incidentally, led in JDP's most recent Sales Satisfaction Survey, followed by Cadillac and Lexus. This measures buyer attitudes about dealer sales experience. And the results are no surprise to Rosemary Shahan, founder of Consumers for Auto Safety and Reliability (CARS), which also tracks customer attitudes.

“Every year, Saturn has been far away the best,” Ms. Shahan says. “Not that their products are perfect. Nobody's are. Mercedes makes lemons. So does Rolls-Royce, every now and then. But when there's a problem, they're very democratic and forward-thinking in how they address it.

“It doesn't matter who you are. If you're a single mom and this is the only car you've ever bought from them, they take care of you.”

“The IQS is much more forgiving than the long-term quality results,” Mr. Ivers admits. In this study (latest released last November), the industry average PP100 is PP448 — some three times that of the initial quality study. In other words, more things go wrong as age and mileage pile up. No surprise there, but again the Japanese dominate in durability. Mr. Ivers says a four- or five-year-old factory-refreshed Toyota and Honda car typically can command $1,500 to $,1800 more than comparable U.S. or European makes.

“It's a tough challenge on the market's low end,” to compete on quality, he says. “You've got to pick your battles.”

Improvement in IQS scores is easier than making headway on the durability side because “They can fix things while they're still building the vehicles, but on durability you don't find out until four or five years later. Manufacturing has an effect on IQS because you can spot the defects and make fixes. But when you get higher mileage, it has more to do with design and supplier selections. It's tough to maintain your reputation.”

Despite its low ranking at JDP events, Mr. Ivers says: “Ford hasn't gotten worse over the years, but the industry average has been going up.” In short, the quality race is getting tougher.