The Tatas have something to smile about. Its luxury brand Jaguar surged to the top of JD Power and Associates' closely watched vehicle dependability study this year, tying Buick for the No.1 spot and dethroning Lexus for the first time since the Japanese luxury brand became a part of the survey.

Lexus, Toyota Motor Corp.'s luxury brand, took the next spot in the study released Thursday, followed by Toyota's namesake brand, then Mercury, Infiniti and Acura.

"Buick and Jaguar both lead the industry in nameplate performance," said Neal Oddes, director of product research and analysis at JD Power. "In terms of individual model performance, Lexus and Toyota still do very, very well."

"Buick has ranked among the top 10 nameplates each year since the study was last redesigned in 2003, while Jaguar has moved rapidly up the rankings," said David Sargent, vice president of automotive research at JD Power. "Lexus remains a very strong competitor in long-term quality. In particular, the Lexus LS 430 sets the industry standard for dependability, with fewer problems reported than any other model in the study."

The annual study measures problems experienced by the original owners of vehicles after three years. Ina a disappointment for Maruti owners, Suzuki owners reported the most problems among the 37 brands assessed by JD Power.

Toyota garners five segment awards – more than any other nameplate in 2009 – for the Highlander, Prius, Sequoia, Solara and Tundra. Lexus follows with four segment awards for the ES 330 (in a tie with the Acura RL), GX 470, LS 430 and SC 430. Lincoln captures two awards for the Mark LT and Zephyr. Models by Acura, Buick, Dodge, Ford, Honda, Mazda, Mercury, Nissan and Scion each rank highest in one segment.

Jaguar's sudden jump to the top from its No. 10 spot in 2008 was notable for a study that is fairly consistent from year to year. Oddes said the brand has made significant improvements across many areas.

"We see improvements all over the board with Jaguar," Oddes said, citing fewer reported problems with vehicle exterior, sound system and the overall driving experience. "The improvement at a nameplate level is significant." Still, Jaguar, Tata Motors Ltd. bought from Ford in 2007, remains a relatively small-volume brand in the US. It sold just 14,000 vehicles in 2008, while Buick sold 128,000.

The study, which measures problems experienced by original owners of three-year-old (2006 model year) vehicles, has been redesigned to include 202 different problem symptoms across all areas of the vehicle. Overall dependability is determined by the level of problems experienced per 100 vehicles (PP100), with a lower score reflecting higher quality. The study is used extensively by vehicle manufacturers worldwide to help design and build better vehicles--which typically retain higher resale values--and by consumers to help them make more-informed choices for both new and used vehicles.

"In the current economic climate, consumers are delaying new-vehicle purchases and keeping their vehicles longer – the average age of a vehicle at trade-in has increased to 73 months in 2009 from 65 months in 2006," said Sargent. "This makes vehicle dependability even more critical. Automakers have improved long-term dependability by an average of 10 percent each year since the inception of the study, which is a testament to the industry's commitment to continuously improve and sustain quality, especially long-term quality. Making improvements in long-term quality not only satisfies customers who are holding onto their vehicles longer, but it will also influence their decisions when they return to the new-vehicle market or are seeking to purchase a pre-owned vehicle."

The study finds that the frequency and severity of component replacement has a particularly strong impact on customer loyalty intentions. Component areas for which the impact is greatest include engine and transmission. When engine components are replaced or rebuilt, just 11 per cent of customers state that they definitely intend to purchase or lease another vehicle of the same make, compared with nearly 40 per cent among owners who report replacing no components.

Headquartered in Westlake Village, California, JD Power and Associates is a global marketing information services company operating in key business sectors including market research, forecasting, performance improvement, Web intelligence and customer satisfaction. The company's quality and satisfaction measurements are based on responses from millions of consumers annually.

Brand Problems per 100 vehicles

Top Three Models per Segment

Sub-Compact Car

Scion xA

Suzuki Aerio

Chevrolet Aveo

Compact Car

Toyota Prius

Toyota Matrix

Pontiac Vibe

Compact Sporty Car

Mazda MX-5 Miata

Subaru Impreza

Pontiac Solstice Convertible

Midsize Sporty Car

Toyota Solara

Chevrolet Monte Carlo

Ford Mustang

Midsize Car

Buick LaCrosse

Toyota Camry

Mercury Milan

Large Car

Mercury Grand Marquis

Buick Lucerne

Mercury Montego

Compact Premium Sporty Car

Nissan 350Z

Mercedes-Benz SLK-Class

Acura RSX

Entry Premium Vehicle

Lincoln Zephyr

Cadillac CTS

Infiniti G-Series

Midsize Premium Car

Acura RL (tie)

Lexus ES 330 (tie)

Infiniti M-Series

Large Premium Car

Lexus LS 430

Lincoln Town Car

Cadillac DTS

Premium Sporty Car

Lexus SC 430

Porsche 911

Chevrolet Corvette

Compact MAV

Honda Element

Honda CR-V

Mitsubishi Outlander

Midsize MAV

Toyota Highlander

Toyota 4Runner

Buick Rainier

Large MAV

Toyota Sequoia

Chevrolet Tahoe

Ford Expedition

Large Pickup

Toyota Tundra

Ford F-150 LD

GMC Sierra LD

Midsize Pickup

Ford Ranger

Honda Ridgeline

Toyota Tacoma

Van

Dodge Caravan

Ford Freestar

Toyota Sienna

Midsize Premium MAV

Lexus GX 470

Acura MDX

Lexus RX 330/RX400h

Large Premium MAV

Lincoln Mark LT

Land Rover Range Rover Sport

Lincoln Navigator