2021 BMW 1 Series — MOT failures & pass rate
43,176 MOT tests on the 2021 BMW 1 Series are in this dataset, and 92.5% of them passed. That is effectively the same as small family cars of a similar age (8.3% fail rate), so the MOT record here is unremarkable in either direction. Failures cluster in tyres, lighting & signalling and brakes.
What the MOT record shows
One area stands out: tyres, recorded in 5.3% of tests against 1.3% for the next-worst category.
At component level the recurring items are tread depth, headlamp aim and brake pads — tread depth alone was recorded 620 times.
Mileage matters less than usual here: the 2021 1 Series fails 6.4% of the time in the 0-30k band and 9.1% at 120-150k, a spread of only 2.7 points.
The petrol cars hold up better: 7.2% fail against 9.1% for diesel, a 1.9-point gap across 43,174 tests.
Tyres is the most common advisory, noted on 21.1% of tests — work that passed today but is likely due soon.
The trend is worsening — 2.3% of tests failed in 2021 against 7.6% in 2025, the usual pattern as a fleet ages.
How it compares
Top failure categories
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Tyres | 5.3% | 2,298 |
| 2 | Lighting & signalling | 1.3% | 539 |
| 3 | Brakes | 0.9% | 394 |
| 4 | Visibility | 0.7% | 310 |
| 5 | Suspension | 0.4% | 191 |
| 6 | Emissions & environmental | 0.3% | 117 |
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 | 620 |
| 2 | Headlamp aim | 503 |
| 3 | Brake pads | 404 |
| 4 | Washers | 202 |
| 5 | Registration plates | 137 |
| 6 | Wipers | 135 |
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 | 21.1% | 9,101 |
| 2 | Brakes | 6.2% | 2,696 |
| 3 | Other defects | 4.5% | 1,922 |
| 4 | Visibility | 1.8% | 761 |
| 5 | Suspension | 0.7% | 315 |
| 6 | Road wheels | 0.7% | 301 |
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 | 24,304 | 6.4% |
| 30-60k | 16,998 | 8.6% |
| 60-90k | 1,612 | 12.2% |
| 90-120k | 221 | 13.6% |
| 120-150k | 33 | 9.1% |
Failure rate by age
By fuel type
| Fuel | Tests | Fail rate |
|---|---|---|
| Petrol | 35,789 | 7.2% |
| Diesel | 7,385 | 9.1% |
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2021 | 43 | 2.3% |
| 2023 | 1,793 | 4.5% |
| 2024 | 20,810 | 7.8% |
| 2025 | 20,508 | 7.6% |
What to check before buying a 2021 1 Series
The failure pattern for this year is specific enough to inspect against: tyres accounted for 5.3% of tests. Start there.
- Tyres (5.3% 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.
- Lighting & signalling (1.3% of tests): Often a cheap bulb, but persistent issues can mean wiring or corrosion in the units. Typical repair: £10–£150.
- Brakes (0.9% 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 2021 BMW 1 Seriess pass their MOT?
92.5% of the 43,176 2021 BMW 1 Series MOT tests in this dataset passed — a 7.5% fail rate.
What is the most common MOT failure on a 2021 BMW 1 Series?
Tyres, recorded in 5.3% of tests, followed by lighting & signalling (1.3%).
Does the 2021 1 Series get worse with mileage?
Its MOT fail rate rises from 6.4% in the 0-30k band to 9.1% in the 120-150k band.
Methodology & source. Based on 43,176 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.