MOT cost .

MG

B

3,145 MOT tests analysed. sits above the UK fleet average — here's where Bs pass, fail, and end up on the retest sheet.

That's 4.8 points above the UK fleet average across our 1,988 tracked models — a confident result.

Pass

80.6%

Pass-after-fix

2.4%

Fail

16.2%

Avg miles

43,923

Pass + Pass-after-fix + Fail = 100%

The picture

B: above-average pass rates, with caveats

Across 3,145 MOT tests, the B returns 80.6% first-time pass — above the UK fleet average. The single most-logged Major fail is emissions levels exceed default limits. Brakes imbalance across an axle such and a missing steering gaiter round out the top three. Average tested mileage sits at 43,923, which is the lens to read those failure rankings through. If you own one and the next test is close, the ranked list below is a sensible pre-test checklist.

Top ten reasons for rejection.

  1. 01

    Emissions levels exceed default limits

    77 occurrences · 2.4% of tests

  2. 02

    Brakes imbalance across an axle such that the braking effort from any wheel is less than 70% of the maximum effort recorded from the other wheel on the same axle.

    71 occurrences · 2.3% of tests

  3. 03

    Steering rack gaiter or ball joint dust cover missing or no longer prevents the ingress of dirt etc

    65 occurrences · 2.1% of tests

  4. 04

    A lamp missing, inoperative or in the case of a multiple light source more than 1/2 not functioning

    57 occurrences · 1.8% of tests

  5. 05

    Windscreen washers not working or not providing sufficient fluid to clear the windscreen

    53 occurrences · 1.7% of tests

  6. 06

    Significant brake effort recorded with no brake applied indicating a binding brake

    50 occurrences · 1.6% of tests

  7. 07

    Audible warning inoperative

    48 occurrences · 1.5% of tests

  8. 08

    A headlamp or light source missing, inoperative or more than ½ not functioning in the case of LED

    47 occurrences · 1.5% of tests

  9. 09

    Windscreen washers not working or not providing sufficient fluid to clear the windscreen

    44 occurrences · 1.4% of tests

  10. 10

    Stop lamps all missing or inoperative

    41 occurrences · 1.3% of tests

Counts cover Major and Dangerous defects logged at test. Advisory items excluded so this shows why a car was rejected, not just what the tester flagged in passing.

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Buying or keeping a B?

Use the failure ranking as a pre-test checklist or a haggling lever. Treat the headline pass rate as a fleet-wide trend, not a guarantee on any individual car.

If you own a B and your last MOT looked nothing like the ranked failures above, that's normal — individual cars vary widely. The ranking shows the patterns testers flag most often across the country.