2021 BMW M4 Competition — MOT failures & pass rate
Across 1,396 MOT tests, the 2021 BMW M4 Competition recorded a 93.4% pass rate. Against all cars of a similar age (8.6% fail rate), the 2021 M4 Competition comes out 2.0pp better. Failures cluster in tyres, other defects and lighting & signalling.
What the MOT record shows
One area stands out: tyres, recorded in 4.6% of tests against 1.4% for the next-worst category.
At component level the recurring items are registration plates, tread depth and headlamp aim — registration plates alone was recorded 33 times.
Tyres is the most common advisory, noted on 13.4% of tests — work that passed today but is likely due soon.
The trend is worsening — 0.0% of tests failed in 2023 against 6.6% in 2025, the usual pattern as a fleet ages.
How it compares
Top failure categories
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Tyres | 4.6% | 64 |
| 2 | Other defects | 1.4% | 19 |
| 3 | Lighting & signalling | 1.0% | 14 |
| 4 | Visibility | 0.5% | 7 |
| 5 | Emissions & environmental | 0.3% | 4 |
| 6 | Suspension | 0.2% | 3 |
Most common specific failures
The exact components most often recorded as failures — more specific than the categories above.
| # | Failure item | Times recorded |
|---|---|---|
| 1 | Registration plates | 33 |
| 2 | Tread depth | 26 |
| 3 | Headlamp aim | 9 |
| 4 | Side repeaters | 9 |
| 5 | Windscreen | 3 |
| 6 | Washers | 3 |
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 | 13.4% | 187 |
| 2 | Other defects | 2.5% | 35 |
| 3 | Visibility | 1.2% | 17 |
| 4 | Brakes | 1.1% | 15 |
| 5 | Steering | 0.4% | 6 |
| 6 | Lighting & signalling | 0.2% | 3 |
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 | 1,040 | 5.5% |
| 30-60k | 336 | 9.2% |
Failure rate by age
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2023 | 45 | 0.0% |
| 2024 | 656 | 7.0% |
| 2025 | 695 | 6.6% |
What to check before buying a 2021 M4 Competition
The failure pattern for this year is specific enough to inspect against: tyres accounted for 4.6% of tests. Start there.
- Tyres (4.6% 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.
- Other defects (1.4% of tests): Miscellaneous items not in the main categories. Typical repair: varies.
- Lighting & signalling (1.0% of tests): Often a cheap bulb, but persistent issues can mean wiring or corrosion in the units. Typical repair: £10–£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 BMW M4 Competitions pass their MOT?
93.4% of the 1,396 2021 BMW M4 Competition MOT tests in this dataset passed — a 6.6% fail rate.
What is the most common MOT failure on a 2021 BMW M4 Competition?
Tyres, recorded in 4.6% of tests, followed by other defects (1.4%).
Does the 2021 M4 Competition get worse with mileage?
Its MOT fail rate rises from 5.5% in the 0-30k band to 9.2% in the 30-60k band.
Methodology & source. Based on 1,396 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.