Know Your MOT

MG B vs MG 3: MOT reliability compared

Updated 05 September 2026.

18.6%
MG 3 MOT failure rate, 4.6 pts lower than MG B

MG 3 is the more reliable MOT performer: 18.6% of MG 3 MOTs fail versus 23.2% for MG B, a 4.6 point gap.

MetricMG BMG 3
MOT failure rate23.2%18.6%
Tests analysed341,344170,040
Most common failureLamps & electrical (40.9%)Tyres (27.2%)

Questions and answers

Which is more reliable, MG B or MG 3?

MG 3 is the more reliable MOT performer: 18.6% of MG 3 MOTs fail versus 23.2% for MG B, a 4.6 point gap.

What is the MOT failure rate of the MG B?

23.2% of MG B MOT tests result in a failure, from 341,344 tests.

What is the MOT failure rate of the MG 3?

18.6% of MG 3 MOT tests result in a failure, from 170,040 tests.

Compared here

MG B common MOT failures and failure rateMG 3 common MOT failures and failure rate