MOT failure rate and common problems for the MG Zb, and how to check your own car by registration.
Updated 05 September 2026.
MG Zb MOT failure rate
What a MG Zb fails its MOT on, and the part that fixes each.
What it fails on, and why
Suspension failures usually mean a worn or snapped coil spring, a leaking shock absorber, or play in a lower arm ball joint or bush. The tester checks for corrosion, fractures and excessive movement. A broken front spring is one of the most common failures on higher-mileage cars and is a straightforward replacement.
Visibility failures include torn or smearing wiper blades, a washer jet that does not reach the screen, and chips or cracks in the driver's swept area. Blades and washer fluid are quick, cheap fixes.
Lighting is the single most common MOT failure and the cheapest to put right. A blown headlight, brake-light or number-plate bulb, a cracked lens, or a headlamp beam that points too high or low will all fail. Most are a two-minute bulb swap.
The parts that fix each
If your car has just failed, you have 10 working days to fix the items and get a free partial retest. Confirm the exact fitment against your registration or VIN before buying.
Other models
Questions and answers
What is the MOT failure rate of the MG Zb?
It fails 9.0% of its MOT tests across the DVSA record, from 67 tests.
What do these cars fail their MOT on most?
The most common failure area is suspension, at 50.0% of this model's failures.