2021 BMW 3 Series — MOT failures & pass rate
58,623 MOT tests on the 2021 BMW 3 Series are in this dataset, and 89.4% of them passed. That is effectively the same as executive cars of a similar age (9.8% fail rate), so the MOT record here is unremarkable in either direction. Failures cluster in tyres, lighting & signalling and visibility.
What the MOT record shows
One area stands out: tyres, recorded in 7.8% of tests against 1.9% for the next-worst category.
At component level the recurring items are tread depth, headlamp aim and washers — tread depth alone was recorded 1,388 times.
Condition tracks the odometer closely. Failures run at 8.5% in the 0-30k band and 30.9% in the 150k+ band, a 22.4-point spread — more than double.
The petrol cars hold up better: 8.9% fail against 11.7% for hybrid, a 2.7-point gap across 47,656 tests.
Tyres is the most common advisory, noted on 18.9% of tests — work that passed today but is likely due soon.
The trend is improving — the fail rate fell from 14.6% in 2021 to 10.2% in 2025, as the worst-kept examples leave the fleet.
How it compares
Top failure categories
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Tyres | 7.8% | 4,556 |
| 2 | Lighting & signalling | 1.9% | 1,110 |
| 3 | Visibility | 1.1% | 643 |
| 4 | Suspension | 0.8% | 480 |
| 5 | Brakes | 0.6% | 366 |
| 6 | Seat belts & restraints | 0.4% | 209 |
Most common specific failures
The exact components most often recorded as failures — more specific than the categories above.
| # | Failure item | Times recorded |
|---|---|---|
| 1 | Tread depth | 1,388 |
| 2 | Headlamp aim | 1,278 |
| 3 | Washers | 400 |
| 4 | Ball joint | 339 |
| 5 | Brake pads | 294 |
| 6 | Wipers | 265 |
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 | 18.9% | 11,072 |
| 2 | Other defects | 5.1% | 2,974 |
| 3 | Brakes | 3.9% | 2,301 |
| 4 | Visibility | 2.8% | 1,636 |
| 5 | Suspension | 2.5% | 1,458 |
| 6 | Emissions & environmental | 0.8% | 460 |
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 | 19,433 | 8.5% |
| 30-60k | 29,225 | 11.1% |
| 60-90k | 7,881 | 12.9% |
| 90-120k | 1,738 | 13.8% |
| 120-150k | 304 | 16.4% |
| 150k+ | 42 | 30.9% |
Failure rate by age
By fuel type
| Fuel | Tests | Fail rate |
|---|---|---|
| Hybrid | 28,540 | 11.7% |
| Petrol | 19,116 | 8.9% |
| Diesel | 10,963 | 10.8% |
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2021 | 89 | 14.6% |
| 2022 | 52 | 3.9% |
| 2023 | 1,669 | 7.0% |
| 2024 | 28,963 | 11.2% |
| 2025 | 27,850 | 10.2% |
What to check before buying a 2021 3 Series
The failure pattern for this year is specific enough to inspect against: tyres accounted for 7.8% of tests. Start there.
- Tyres (7.8% 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.
- Lighting & signalling (1.9% of tests): Often a cheap bulb, but persistent issues can mean wiring or corrosion in the units. Typical repair: £10–£150.
- Visibility (1.1% 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 BMW 3 Seriess pass their MOT?
89.4% of the 58,623 2021 BMW 3 Series MOT tests in this dataset passed — a 10.6% fail rate.
What is the most common MOT failure on a 2021 BMW 3 Series?
Tyres, recorded in 7.8% of tests, followed by lighting & signalling (1.9%).
Does the 2021 3 Series get worse with mileage?
Its MOT fail rate rises from 8.5% in the 0-30k band to 30.9% in the 150k+ band.
Methodology & source. Based on 58,623 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.