Toyota Motor Corp.’s Lexus luxury brand continues to polish its quality image, as it tops all other brands in the J.D. Power and Associates 2006 Vehicle Dependability Study (VDS).

The ranking marks the 12th consecutive year Lexus has taken honors in the VDS, which tracks problems experienced by nearly 48,000 owners of 3-year-old, ’03 model year vehicles.

Lexus’ rating of 136 problems per 100 vehicles (PP100) is well below the industry average of 227, down from 237 in 2005. Mercury, Buick, Cadillac and Toyota, respectively, make up the rest of the top five marques, all with less than 180 PP100.

Honda is the only other high-volume brand to garner a top-10 ranking, scoring 194 PP100.

Out of 37 brands, only 13 better the industry average, down from 14 in 2005, the study shows.

This year’s VDS also uncovers a narrowing of the long-term quality gap between luxury and high-volume brands, evidenced by three of the top five marques in the study being non-luxury makes.

“The industry continues to make improvements in long-term vehicle quality, and not just among luxury makes that benefit from smaller production volumes on the assembly line,” notes Neal Oddes, J.D. Power director of product research and analysis.

J.D. Power pegs the gap between luxury and non-luxury brands at 15 PP100, down from 31 in 2003, with major improvements coming in ride, handling and braking and powertrains.

Of all the nameplates, Mini and Kia were the most improved, with year-over-year gains of 27% and 22%, respectively.

Porsche represented one of the biggest disappointments, falling from second place in 2005 (149 PP100) to 22nd this year (248 PP100). General Motors Corp.’s Saturn unit also nose dived, dropping 16 places, with PP100 increasing from 240 last year to 289 in 2006.

Overall, Land Rover fared the worst in 2006, scoring 438 PP100, up from 395 last year and more than 100 PP100 higher than second-to-last Saab.

Lexus and Toyota also performed well in individual vehicle sectors, scoring top honors in four segments each. Honda vehicles were rated the best in three segments.

Other segment winners include: Acura (CL), Buick (Century), Cadillac (Escalade EXT), Chevrolet (Monte Carlo), Ford (Ranger), Mazda (Miata), Mercury (Grand Marquis) and GMC (Yukon/Yukon XL).

Along with retaining their value better, brands with strong VDS results generally have higher levels of owner recommendation and repurchase intent and increased sales volumes compared with brands with average-to-poor ratings, J.D. Power says. Brands with higher scores are more likely to have higher failure rates for components, such as brakes and batteries, the researcher says.

“In terms of retained value, recommendation and repurchase intent and component replacement, vehicle dependability can have a direct impact on a manufacturer’s bottom line,” Oddes says.