1980 Mg B — MOT failures & pass rate

Across 659 MOT tests analysed for the 1980 Mg B, the most common recorded failure areas were lighting & signalling, emissions & environmental and brakes. Its pass rate of 81.5% was below the average for cars of a similar age (84.1%). Higher-mileage examples failed more often — 23.5% in the 90-120k group versus 14.5% in the 0-30k group.

Pass rate

659

MOT tests analysed

18.5%

Fail rate

worse than

vs cars of similar age

42.7

Avg age at test (yrs)

How it compares

Fail rate for this model-year against the segment and national averages for cars of a similar age.

Top failure categories

Most common MOT failure areas — 1980 Mg B
#	Category	% of tests affected	Tests
1	Lighting & signalling	9.9%	65
2	Emissions & environmental	7.6%	50
3	Brakes	7.4%	49
4	Visibility	6.7%	44
5	Body, structure & corrosion	3.2%	21
6	Steering	2.7%	18

Percentage of tests with at least one failure recorded in each category.

Most common specific failures

The exact components most often recorded as failures — more specific than the categories above.

Most frequently recorded failure items — 1980 Mg B
#	Failure item	Times recorded
1	Non catalyst emissions	59
2	Washers	36
3	Service brake performance	24
4	Position lamp	19
5	Service brake imbalance	19
6	Rear fog lamp	18

Top advisory categories

Advisories aren't failures, but they flag work likely needed soon — useful when budgeting.

Most common MOT advisories — 1980 Mg B
#	Category	% of tests with advisory	Tests
1	Suspension	17.2%	113
2	Emissions & environmental	14.7%	97
3	Brakes	7.6%	50
4	Body, structure & corrosion	6.1%	40
5	Other defects	5.9%	39
6	Tyres	4.3%	28

Failure rate by mileage

Higher-mileage cars tend to fail more — often the most useful guide to real condition.

MOT fail rate by recorded mileage band.

Fail rate by recorded mileage — 1980 B
Mileage band	Tests	Fail rate
0-30k	152	14.5%
30-60k	205	21.9%
60-90k	234	16.7%
90-120k	68	23.5%

Trend over time

Fail rate by dataset year — 1980 B
Dataset year	Tests	Fail rate
2021	180	16.1%
2022	134	17.9%
2023	130	22.3%
2024	105	18.1%
2025	110	19.1%

What to check before buying a 1980 B

Before buying a 1980 Mg B, focus on the areas it most often fails on. Lighting & signalling accounted for 9.9% of tests for this year.

Lighting & signalling (9.9% of tests): Often a cheap bulb, but persistent issues can mean wiring or corrosion in the units. Typical repair: £10–£150.
Emissions & environmental (7.6% of tests): More common on older diesels (DPF/EGR) — can be expensive; check for warning lights and smoke. Typical repair: £100–£600.
Brakes (7.4% of tests): Pads/discs are routine wear; binding, imbalance or corroded pipes are more serious — test for pulling under braking. Typical repair: £100–£350 per axle.

Repair costs are rough UK ballpark ranges to set expectations, not quotes — actual prices vary widely by car, parts and garage.

Frequently asked questions

How many 1980 Mg Bs pass their MOT?

81.5% of the 659 1980 Mg B MOT tests in this dataset passed — a 18.5% fail rate.

What is the most common MOT failure on a 1980 Mg B?

Lighting & signalling, recorded in 9.9% of tests, followed by emissions & environmental (7.6%).

Does the 1980 B get worse with mileage?

Its MOT fail rate rises from 14.5% in the 0-30k band to 23.5% in the 90-120k band.

Methodology & source. Based on 659 MOT tests. Dataset: DVSA MOT testing data (2021,2022,2023,2024,2025). Data last updated 2026-07-01. Figures reflect MOT-testable defects only — read the methodology for how these are calculated and what they don't measure.