MG B MOT Check

MOT pass rates, common failures, and reliability data for the MG B. Check any B by registration number below.

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82.5%

Avg Pass Rate

-0.6%

vs MG Avg

Year Ranges

Good

Reliability

MG B — MOT Reliability Overview

The MG B has an average MOT pass rate of 82.5%, which is 0.6 percentage points below the MG brand average of 83.1%. This is a strong result, indicating that the B is well-engineered and tends to age well mechanically. Owners can expect fewer surprises at MOT time.

The most common reasons a MG B fails its MOT are emissions levels exceed default limits, a rear registration plate lamp or light source missing or inoperative in the case of a single lamp or all lamps, audible warning inoperative. If you are preparing your B for its MOT, checking these areas first could save you a retest fee. Our detailed fault analysis includes estimated repair costs for each failure type.

Before buying a used MG B, we recommend checking the full MOT history, write-off status, outstanding finance, and stolen vehicle status. These checks can be done for free using the registration number.

MOT Pass Rate by Year

How the MG B performs at MOT across different model years.

1982

Based on 50 vehicles

88.0%Excellent

MG average: 83.1%

Dangerous Defects

3.2%

Retest Rate

3.2%

1981

Based on 291 vehicles

84.2%Good

MG average: 83.1%

Dangerous Defects

3.5%

Retest Rate

12.9%

1980

Based on 220 vehicles

77.3%Good

MG average: 83.1%

Dangerous Defects

0.9%

Retest Rate

19.0%

1979

Based on 280 vehicles

82.1%Good

MG average: 83.1%

Dangerous Defects

1.9%

Retest Rate

16.8%

1978

Based on 427 vehicles

85.0%Excellent

MG average: 83.1%

Dangerous Defects

0.8%

Retest Rate

10.1%

1977

Based on 316 vehicles

79.4%Good

MG average: 83.1%

Dangerous Defects

1.1%

Retest Rate

12.1%

1976

Based on 218 vehicles

73.9%Average

MG average: 83.1%

Dangerous Defects

5.8%

Retest Rate

23.4%

1975

Based on 269 vehicles

84.4%Good

MG average: 83.1%

Dangerous Defects

3.7%

Retest Rate

12.2%

1974

Based on 406 vehicles

84.0%Good

MG average: 83.1%

Dangerous Defects

1.7%

Retest Rate

10.1%

1973

Based on 650 vehicles

82.6%Good

MG average: 83.1%

Dangerous Defects

3.4%

Retest Rate

15.3%

1972

Based on 683 vehicles

86.2%Excellent

MG average: 83.1%

Dangerous Defects

1.5%

Retest Rate

11.4%

0

Based on 3,145 vehicles

83.0%Good

MG average: 83.1%

Mileage at 5yr

44k mi

Top MOT Failures — MG B

The most common reasons a MG B fails its MOT, aggregated across all year ranges.

Emissions levels exceed default limits

3.6%

A rear registration plate lamp or light source missing or inoperative in the case of a single lamp or all lamps

1.9%

Audible warning inoperative

1.5%

MG B Common Faults & Repair Costs

Where Failures Occur

The areas of the vehicle most commonly flagged during MOT inspections.

Front Offside

12.0%

Front Nearside

12.0%

Rear Offside

10.0%

Other MG Models

Compare MOT reliability across MG models.

MG ZR

74.1% pass rate

MG 6

64.3% pass rate

MG 3

76.5% pass rate

MG MGB

70.0% pass rate

MG Mgb Roadster

95.5% pass rate

MG B Gt

75.0% pass rate

Useful MOT Guides

Common MOT Failures

The most common reasons UK vehicles fail their MOT — and how to prepare.

MOT Checklist

Pre-MOT checklist to improve your chances of passing first time.

Advisory vs Failure

Understanding the difference between MOT advisories and failures.

See detailed fault analysis for MG B

MG B — Frequently Asked Questions

Common questions about the MG B MOT and reliability.

What is the MOT pass rate for the MG B?

The average MOT pass rate for the MG B is 82.5% compared to the MG average of 83.1%. Pass rates vary by year — check the year-by-year breakdown on this page for details.

What are the most common MOT failures on a MG B?

The most common MOT failures on the MG B are: Emissions levels exceed default limits (3.6%), A rear registration plate lamp or light source missing or inoperative in the case of a single lamp or all lamps (1.9%), Audible warning inoperative (1.5%). These are the components most likely to cause an MOT failure.

Is the MG B reliable?

With an average MOT pass rate of 82.5%, the MG B is rated as "Good" for reliability. This is a strong result suggesting good build quality and fewer common defects.

How do I check the MOT history of a MG B?

Enter the vehicle's registration number in the search box at the top of this page. You will instantly see the complete MOT history including every test result, mileage readings, advisories, and dangerous defects — completely free.

What mileage should I expect on a MG B?

Typical mileage for the MG B: 43,923 miles at 5 years. Use these benchmarks when evaluating a used B to spot vehicles with unusually high or low mileage.

Check Your MG B's MOT History

Enter the registration number for the full MOT history — free and instant.