Mazda's roadster tops Reliability Index

If Renault’s new roadster is really going to trouble the MX-5, it will need to match its opponent’s famed build quality. And that won’t be easy – because the Japanese model has finished top in a reliability study of 450,000 convertibles.

Maintenance cover provider War­ranty Direct devised the list from claims it received for mechanical failures. It calculated how long each car was likely to spend in a garage each year, and combined that with the average repair bill to produce a Reliability Index (RI).

The MX-5 did best with a score of 7.29, based on 1.06 days off the road and an average repair bill of £255.59. Honda’s S2000 came in second with an RI of 34.31. It was likely to spend 1.43 days in a workshop with a bill averaging £343.12.

In third, with an RI of 51.95, was the Peugeot 207 CC. At £225.76 it was cheap to mend, but was set to spend 2.15 days a year being fixed.