Know Your MOT

Smart Roadster vs Smart Forfour: MOT reliability compared

Updated 05 September 2026.

25.6%
Smart Roadster MOT failure rate, 1.2 pts lower than Smart Forfour

Smart Roadster is the more reliable MOT performer: 25.6% of Smart Roadster MOTs fail versus 26.8% for Smart Forfour, a 1.2 point gap.

MetricSmart RoadsterSmart Forfour
MOT failure rate25.6%26.8%
Tests analysed77,22874,542
Most common failureLamps & electrical (41.7%)Lamps & electrical (34.4%)

Questions and answers

Which is more reliable, Smart Roadster or Smart Forfour?

Smart Roadster is the more reliable MOT performer: 25.6% of Smart Roadster MOTs fail versus 26.8% for Smart Forfour, a 1.2 point gap.

What is the MOT failure rate of the Smart Roadster?

25.6% of Smart Roadster MOT tests result in a failure, from 77,228 tests.

What is the MOT failure rate of the Smart Forfour?

26.8% of Smart Forfour MOT tests result in a failure, from 74,542 tests.

Compared here

Smart Roadster common MOT failures and failure rateSmart Forfour common MOT failures and failure rate