The Mazda MX-5 has been named as the most reliable convertible in Britain following a survey of more than 50,000 cars by What Car? magazine.

Mazda MX-5 sportscars manufactured since 2005 recorded a failure rate of just 4% – the lowest of all cars in the 2012 survey – compared to the next nearest open-top competitor at 15%.

The results follow on the back of What Car?’s overall survey which highlighted Honda as the most reliable brand. 

Japanese brands represented eight of the top 10 most reliable brands in the survey.

The MX-5 also achieved a reliability index (RI) score of just eight (the lower score, the better the car), while the national average score for individual models was 100.

According to the survey, MX-5 owners also benefit from the lowest repair costs with an average repair bill of just £165.

The survey calculates a vehicle’s RI from several factors – the number of times it fails, the cost of repair, the average time it spends off the road being repaired, its age and mileage.

Read AM's latest MX-5 long term road test report.