Know Your MOT

MG Zr vs MG B: MOT reliability compared

Updated 05 September 2026.

23.2%
MG B MOT failure rate, 7.0 pts lower than MG Zr

MG B is the more reliable MOT performer: 23.2% of MG B MOTs fail versus 30.2% for MG Zr, a 7.0 point gap.

MetricMG ZrMG B
MOT failure rate30.2%23.2%
Tests analysed654,579341,344
Most common failureLamps & electrical (38.5%)Lamps & electrical (40.9%)

Questions and answers

Which is more reliable, MG Zr or MG B?

MG B is the more reliable MOT performer: 23.2% of MG B MOTs fail versus 30.2% for MG Zr, a 7.0 point gap.

What is the MOT failure rate of the MG Zr?

30.2% of MG Zr MOT tests result in a failure, from 654,579 tests.

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.

Compared here

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