Efforts by U.S. auto makers to improve fuel economy and give technology-hungry consumers more multimedia has led to a decline in the initial quality of newly launched vehicles, consultant J.D. Power & Associates says in an annual study.

The good news is overall initial quality improved again this year, with problems per 100 vehicles dropping to 107 from 109 in 2010. The consultancy says 73,790 surveys were returned on 32 brands and 202 models.

J.D. Power says in its report that carryover models, or cars and trucks receiving no major redesign, carried the day for auto makers improving to 103 PP100 from 108 last year.

But new models were the car companies’ Achilles heel this year, with initial quality falling 10% to 122 PP100 from 111 in 2010. Blame efforts to dial up fuel economy through software tweaks to engines and transmissions and the acceleration of multi-media technology offerings such as hands-free and voice-activation systems.

“Exciting models with the latest features are crucial for winning over today’s demanding consumers,” David Sargent, vice president-global vehicle research at J.D., says in a statement.

“However, auto makers must not lose their focus on the importance of these models also achieving exceptional quality levels.

“Expected reliability continues to be the single most-important reason why new-vehicle buyers choose one model over another, and no manufacturer can afford to give consumers any doubts regarding the quality of their latest products.”

According to the firm’s research, which auto makers use as a key quality metric and their dealers boast about to shoppers of well-scoring vehicles, just seven all-new or redesigned models finished among the top three this year in their respective award segments. Last year, 17 models earned that distinction.

Further reflecting the dip in initial quality for new vehicles, only one newly launched model this year received a segment award, compared with five in 2010.

In addition, a slim one-fourth of redesigned vehicles performed better than their predecessors in 2010, and eight all-new models performed better than their respective award segment average.

On poor-scoring new models, J.D. Power says buyers mostly complained of “hesitation” in the engine or transmission while accelerating or changing gears. Others cited hands-free or voice-activation technology that failed to operate as expected.

“Clearly, consumers are interested in having new technology in their vehicles, but auto makers must ensure that the technology is ready for prime time,” Sargent says.

“Successful companies will be those that can take this incredibly complex technology and make it reliable, seamless and easy for owners to operate while they are driving. There is an understandable desire to bring these technologies to market quickly, but auto makers must be careful to walk before they run.”

Among vehicle brands, Lexus emerges as the leader, with 73 PPV100, and its LS sedan as the overall best, followed by Honda, which jumps to second place from sixth last year. Acura, Mercedes-Benz and Mazda, which leaps from fifth to 18th, round out the study’s top five performers.

Land Rover shows the greatest year-over-year improvement, by reducing PPV100 by 47.

Honda wins seven segment awards with the Accord, Accord Crosstour, Civic (in a tie), Element, Fit, Insight (in a tie) and Ridgeline. In addition to the LS, Lexus earns top initial quality scores for the ES, GS and GX models.

Chevrolet, Ford and Mercedes win two awards each, J.D. Power says. General Motors’ bow-tie brand receives nods for the HHR and Tahoe, while Ford’s stalwart F-150 and Taurus show top quality.

The Cadillac Escalade, Chrysler Town & Country, Dodge Challenger and Mazda MX-5 Miata also earn distinction. Mercedes wins for the GLK-Class and the E-Class cabriolet/coupe.

J.D. Power also reports the Hyundai Equus and Dodge Durango posted notably strong performances among redesigned and all-new models.

The research firm does not release to the media initial-quality performance by company, making it difficult to gauge the impact of last year’s recall crisis on traditional leader Toyota.

The IQS report, in its 25th year, measures initial quality based on surveys of buyers after 90 days of ownership.

J.D. Power also recognizes assembly plants building vehicles with the fewest defects and malfunctions. This year’s top performers include Toyota’s Cambridge South, ON, Canada, facility and Kyushu 2, Japan, plant; as well as Honda’s Greensburg, IN, site.

In Europe and Africa, Daimler’s Bremen 1, Germany, and East London, South Africa, facilities tie for a top award, the consultancy group says.

jamend@wardsauto.com