2020 MG MG3 — MOT failures & pass rate
The 2020 MG MG3 passed 89.4% of its 8,279 recorded MOT tests. That is 1.7 percentage points worse than superminis of a similar age, which fail at 8.9%. Failures cluster in lighting & signalling, tyres and brakes.
What the MOT record shows
No single area dominates — lighting & signalling (6.8%) and tyres (6.3%) are close, so failures are spread across several systems rather than one weak point.
At component level the recurring items are headlamp aim, stop lamp and tread depth — headlamp aim alone was recorded 558 times.
Condition tracks the odometer closely. Failures run at 8.4% in the 0-30k band and 22.1% in the 60-90k band, a 13.8-point spread — more than double.
Advisories point at the next bill rather than this one: tyres was flagged on 22.7% of tests without failing them.
The trend is worsening — 1.0% of tests failed in 2022 against 13.0% in 2025, the usual pattern as a fleet ages.
How it compares
Top failure categories
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Lighting & signalling | 6.8% | 566 |
| 2 | Tyres | 6.3% | 518 |
| 3 | Brakes | 2.8% | 230 |
| 4 | Visibility | 1.8% | 150 |
| 5 | Suspension | 1.1% | 90 |
| 6 | Emissions & environmental | 0.4% | 30 |
Most common specific failures
The exact components most often recorded as failures — more specific than the categories above.
| # | Failure item | Times recorded |
|---|---|---|
| 1 | Headlamp aim | 558 |
| 2 | Stop lamp | 128 |
| 3 | Tread depth | 118 |
| 4 | Tyre pressure monitoring system | 92 |
| 5 | Brake pads | 92 |
| 6 | Washers | 85 |
Top advisory categories
Advisories aren't failures, but they flag work likely needed soon — useful when budgeting.
| # | Category | % of tests with advisory | Tests |
|---|---|---|---|
| 1 | Tyres | 22.7% | 1,881 |
| 2 | Brakes | 13.6% | 1,122 |
| 3 | Other defects | 5.8% | 477 |
| 4 | Visibility | 2.7% | 220 |
| 5 | Suspension | 2.4% | 197 |
| 6 | Emissions & environmental | 0.9% | 79 |
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 | 6,235 | 8.4% |
| 30-60k | 1,907 | 17.3% |
| 60-90k | 113 | 22.1% |
Failure rate by age
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2022 | 99 | 1.0% |
| 2023 | 2,669 | 8.4% |
| 2024 | 2,702 | 10.8% |
| 2025 | 2,807 | 13.0% |
What to check before buying a 2020 MG3
On a 2020 MG3, lighting & signalling is what the MOT record says goes wrong most — it appeared in 6.8% of tests. Check these areas before you commit.
- Lighting & signalling (6.8% of tests): Often a cheap bulb, but persistent issues can mean wiring or corrosion in the units. Typical repair: £10–£150.
- Tyres (6.3% of tests): Usually a quick, known-cost fix, but check tread, age and uneven wear (which can hint at alignment or suspension issues). Typical repair: £50–£120 per tyre.
- Brakes (2.8% 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 2020 MG MG3s pass their MOT?
89.4% of the 8,279 2020 MG MG3 MOT tests in this dataset passed — a 10.6% fail rate.
What is the most common MOT failure on a 2020 MG MG3?
Lighting & signalling, recorded in 6.8% of tests, followed by tyres (6.3%).
Does the 2020 MG3 get worse with mileage?
Its MOT fail rate rises from 8.4% in the 0-30k band to 22.1% in the 60-90k band.
Methodology & source. Based on 8,279 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.