1980 MG B/Gt — MOT failures & pass rate
Across 465 MOT tests, the 1980 MG B/Gt recorded a 79.3% pass rate. Against all cars of a similar age (16.2% fail rate), the 1980 B/Gt comes out 4.5pp worse. Failures cluster in lighting & signalling, emissions & environmental and brakes.
What the MOT record shows
One area stands out: lighting & signalling, recorded in 13.6% of tests against 9.9% for the next-worst category.
At component level the recurring items are non catalyst emissions, component mounting prescribed areas and washers — non catalyst emissions alone was recorded 50 times.
Condition tracks the odometer closely. Failures run at 22.1% in the 0-30k band and 27.1% in the 90-120k band, a 5.0-point spread.
Suspension is the most common advisory, noted on 17.0% of tests — work that passed today but is likely due soon.
The trend is improving — the fail rate fell from 22.5% in 2021 to 20.3% in 2025, as the worst-kept examples leave the fleet.
How it compares
Top failure categories
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Lighting & signalling | 13.6% | 63 |
| 2 | Emissions & environmental | 9.9% | 46 |
| 3 | Brakes | 7.1% | 33 |
| 4 | Suspension | 6.7% | 31 |
| 5 | Visibility | 6.0% | 28 |
| 6 | Steering | 3.4% | 16 |
Most common specific failures
The exact components most often recorded as failures — more specific than the categories above.
| # | Failure item | Times recorded |
|---|---|---|
| 1 | Non catalyst emissions | 50 |
| 2 | Component mounting prescribed areas | 24 |
| 3 | Washers | 24 |
| 4 | Headlamp aim | 21 |
| 5 | Position lamp | 21 |
| 6 | Service brake performance | 18 |
Top advisory categories
Advisories aren't failures, but they flag work likely needed soon — useful when budgeting.
| # | Category | % of tests with advisory | Tests |
|---|---|---|---|
| 1 | Suspension | 17.0% | 79 |
| 2 | Emissions & environmental | 15.0% | 70 |
| 3 | Brakes | 7.7% | 36 |
| 4 | Tyres | 6.0% | 28 |
| 5 | Other defects | 5.8% | 27 |
| 6 | Steering | 5.0% | 23 |
Failure rate by mileage
Higher-mileage cars tend to fail more — often the most useful guide to real condition.
| Mileage band | Tests | Fail rate |
|---|---|---|
| 0-30k | 113 | 22.1% |
| 30-60k | 135 | 14.1% |
| 60-90k | 168 | 22.6% |
| 90-120k | 48 | 27.1% |
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2021 | 129 | 22.5% |
| 2022 | 86 | 15.1% |
| 2023 | 92 | 21.7% |
| 2024 | 84 | 22.6% |
| 2025 | 74 | 20.3% |
What to check before buying a 1980 B/Gt
The failure pattern for this year is specific enough to inspect against: lighting & signalling accounted for 13.6% of tests. Start there.
- Lighting & signalling (13.6% of tests): Often a cheap bulb, but persistent issues can mean wiring or corrosion in the units. Typical repair: £10–£150.
- Emissions & environmental (9.9% of tests): More common on older diesels (DPF/EGR) — can be expensive; check for warning lights and smoke. Typical repair: £100–£600.
- Brakes (7.1% 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 B/Gts pass their MOT?
79.3% of the 465 1980 MG B/Gt MOT tests in this dataset passed — a 20.6% fail rate.
What is the most common MOT failure on a 1980 MG B/Gt?
Lighting & signalling, recorded in 13.6% of tests, followed by emissions & environmental (9.9%).
Does the 1980 B/Gt get worse with mileage?
Its MOT fail rate rises from 22.1% in the 0-30k band to 27.1% in the 90-120k band.
Methodology & source. Based on 465 MOT tests. Dataset: DVSA MOT testing data (2021,2022,2023,2024,2025). Data last updated 2026-07-27. Figures reflect MOT-testable defects only — read the methodology for how these are calculated and what they don't measure.