MG B MOT pass rate: 84.7% (2,487 tests, 2025)

The MG B passed 84.7% of its 2,487 MOT tests in 2025 — 7.2 points above the UK average of 77.5%. The median tested example was 53 years old with 39,888 miles on the clock.

84.7%Pass rate (2025)

2,487MOT tests analysed

39,888 miMedian mileage at test

53 yrsMedian age at test

How the B compares

MG B

84.7%

UK average (all Class 4 vehicles)

77.5% across 33.1 million tests

MG average (all models)

84.9%

What fails most on the MG B

Across failed and rectified tests in 2025, these vehicle systems produced the most defects on the B:

#	System	Defects recorded	Share
1	Lamps, reflectors and electrical equipment	327	31.4%
2	Brakes	269	25.8%
3	Suspension	108	10.4%
4	Visibility	106	10.2%
5	Steering	87	8.4%
6	Noise, emissions and leaks	82	7.9%

Pre-MOT checklist for B owners

Based on the failure profile above, ten minutes with a torch before your test removes the most likely fail items:

Walk round with all lights on: one blown bulb is the most avoidable fail there is
Feel for a spongy pedal or pulling to one side; check pad wear through the wheel spokes if visible
Bounce each corner and listen for clonks over speed bumps — suspension is this model’s (and the UK’s) top failure system
Replace smeared wiper blades and top up washer fluid — both are test items
With the engine running, turn lock to lock: knocks or stiff spots are testable defects

Check the engine before the tester does

A stored fault code with the engine light on is an automatic Major defect. Scan and clear resolved faults before booking.

Topdon OBD2 scannersTopdon diagnostic scanners with full-system readouts
XTOOL diagnostic toolsXTOOL code readers for petrol and diesel cars
Autel UK testersAutel professional-grade diagnostic testers

Check a specific B before you buy

Pass rates describe the model; they can’t tell you about the one car you’re looking at. Run its plate through our free MOT history check to see its personal record of failures, advisories and mileage readings.

Other MG models

378.5% pass rate · 19,553 tests ZS79.0% pass rate · 18,837 tests Hs Exclusive S-A92.5% pass rate · 10,003 tests 5 Exclusive90.2% pass rate · 9,518 tests ZS Exclusive EV87.7% pass rate · 9,445 tests ZS Exclusive Vti-Tech88.4% pass rate · 9,373 tests Tf73.7% pass rate · 8,549 tests Hs Exclusive90.9% pass rate · 8,098 tests

FAQs

What is the MOT pass rate for a MG B?

In 2025, 84.7% of 2,487 first MOT tests on the MG B were passes (UK average: 77.5%). Data: DVSA anonymised MOT results.

What does the B fail its MOT on most?

The biggest defect group is lamps, reflectors and electrical equipment (31.4% of its recorded defects), followed by brakes.

Is the MG B reliable?

MOT pass rate is one lens on durability: at 84.7% it performs above the national average at a median age of 53 years and 39,888 miles. Always check the individual car's history too.

Source: DVSA Anonymised MOT tests and results, 2025 extract (Class 4 initial tests only; retests excluded). Contains public sector information licensed under the Open Government Licence v3.0. Figures rounded to one decimal place.