Mazda has topped the Warranty Direct Manufacturer Index (www.reliabilityindex.co.uk) for the last three years.

"Running at below half the Index average, Mazda continues to be head and shoulders above the rest," says Duncan McClure-Fisher of Warranty Direct, which handles thousands of warranty claims every year. "Problems are few and far between, and its cars age well. Infrequent garage visits, quick repair times and reasonable bills have helped consolidate its position."

The Index not only represents the frequency of failure but the actual cost of repair. The average age of the vehicles analysed by Warranty Direct was 4.8 years old with 49,702 miles recorded.

Second place in the Index goes to Ford. Although Ford only records the market average failure rate of 31%, it does deliver the lowest average repair bill of £207.88 in 2003.

The biggest improvement since 2002 came from Nissan, which jumped nine places to 8th in the list of 23 manufacturers analysed. Japan's four leading manufacturers all make it into the top ten, whereas Mercedes (11th), Volkswagen (13th), BMW (16th) and Audi (18th) all slip down the table based on claims handled by Warranty Direct.

At the other end of the table, Jeep, with an average repair bill of £587.92 in 2003 and 41 claims per 100 policies held, remains the worst performer due to failures on air-conditioning units and rear suspension and axle problems.

Subaru's fall of eleven places to 22nd in the table relates to costly repairs to the Impreza's engine and transmission units which pushed the average bill to nearly £1,040, making it the most expensive model repaired in the year so far.

Land Rover and Alfa Romeo remain in the bottom five at 21st and 20th respectively.