2021 MG MG3 — MOT failures & pass rate
Across 4,240 MOT tests, the 2021 MG MG3 recorded a 90.2% pass rate. Superminis of a similar age fail 7.8% of the time, so this is 2.0pp worse than the group it competes with. Failures cluster in lighting & signalling, tyres and visibility.
What the MOT record shows
No single area dominates — lighting & signalling (6.7%) and tyres (5.5%) are close, so failures are spread across several systems rather than one weak point.
At component level the recurring items are headlamp aim, wipers and stop lamp — headlamp aim alone was recorded 295 times.
Condition tracks the odometer closely. Failures run at 8.4% in the 0-30k band and 16.3% in the 60-90k band, a 7.9-point spread.
Tyres is the most common advisory, noted on 24.0% of tests — work that passed today but is likely due soon.
The trend is worsening — 5.0% of tests failed in 2023 against 11.0% in 2025, the usual pattern as a fleet ages.
How it compares
Top failure categories
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Lighting & signalling | 6.7% | 285 |
| 2 | Tyres | 5.5% | 235 |
| 3 | Visibility | 2.2% | 93 |
| 4 | Brakes | 1.8% | 77 |
| 5 | Suspension | 0.9% | 40 |
| 6 | Steering | 0.3% | 11 |
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 | 295 |
| 2 | Wipers | 67 |
| 3 | Stop lamp | 50 |
| 4 | Headlamp | 47 |
| 5 | Tread depth | 47 |
| 6 | Washers | 46 |
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 | 24.0% | 1,019 |
| 2 | Brakes | 12.1% | 513 |
| 3 | Other defects | 6.1% | 258 |
| 4 | Visibility | 2.3% | 99 |
| 5 | Suspension | 1.6% | 67 |
| 6 | Lighting & signalling | 0.8% | 32 |
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 | 3,257 | 8.4% |
| 30-60k | 925 | 14.1% |
| 60-90k | 49 | 16.3% |
Failure rate by age
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2023 | 60 | 5.0% |
| 2024 | 2,049 | 8.7% |
| 2025 | 2,129 | 11.0% |
What to check before buying a 2021 MG3
The failure pattern for this year is specific enough to inspect against: lighting & signalling accounted for 6.7% of tests. Start there.
- Lighting & signalling (6.7% of tests): Often a cheap bulb, but persistent issues can mean wiring or corrosion in the units. Typical repair: £10–£150.
- Tyres (5.5% 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.
- Visibility (2.2% of tests): Wipers, washers, mirrors and screen damage — usually inexpensive, but check for chips in the driver's line of sight. Typical repair: £15–£150.
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 2021 MG MG3s pass their MOT?
90.2% of the 4,240 2021 MG MG3 MOT tests in this dataset passed — a 9.8% fail rate.
What is the most common MOT failure on a 2021 MG MG3?
Lighting & signalling, recorded in 6.7% of tests, followed by tyres (5.5%).
Does the 2021 MG3 get worse with mileage?
Its MOT fail rate rises from 8.4% in the 0-30k band to 16.3% in the 60-90k band.
Methodology & source. Based on 4,240 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.