2020 BMW 4 Series — MOT failures & pass rate
16,014 MOT tests on the 2020 BMW 4 Series are in this dataset, and 90.4% of them passed. Coupes & convertibles of a similar age fail 8.1% of the time, so this is 1.5pp worse than the group it competes with. Failures cluster in tyres, lighting & signalling and visibility.
What the MOT record shows
One area stands out: tyres, recorded in 7.2% of tests against 1.6% for the next-worst category.
At component level the recurring items are tread depth, headlamp aim and brake pads — tread depth alone was recorded 285 times.
Mileage is the strongest signal on the record: 7.7% of 0-30k cars fail, rising to 19.1% once past 90-120k — 2.5× the risk.
Fuel type barely separates them — petrol fails 9.2% of the time against 10.4% for diesel.
Tyres is the most common advisory, noted on 17.0% of tests — work that passed today but is likely due soon.
The trend is worsening — 5.6% of tests failed in 2022 against 10.4% in 2025, the usual pattern as a fleet ages.
How it compares
Top failure categories
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Tyres | 7.2% | 1,150 |
| 2 | Lighting & signalling | 1.6% | 254 |
| 3 | Visibility | 1.1% | 175 |
| 4 | Brakes | 1.1% | 169 |
| 5 | Emissions & environmental | 0.3% | 49 |
| 6 | Suspension | 0.3% | 45 |
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 | 285 |
| 2 | Headlamp aim | 221 |
| 3 | Brake pads | 151 |
| 4 | Washers | 143 |
| 5 | Registration plates | 62 |
| 6 | Wipers | 51 |
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 | 17.0% | 2,714 |
| 2 | Brakes | 9.1% | 1,457 |
| 3 | Other defects | 3.9% | 622 |
| 4 | Visibility | 2.1% | 328 |
| 5 | Suspension | 1.9% | 301 |
| 6 | Road wheels | 0.7% | 112 |
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 | 8,617 | 7.7% |
| 30-60k | 6,494 | 11.7% |
| 60-90k | 787 | 11.9% |
| 90-120k | 94 | 19.1% |
Failure rate by age
By fuel type
| Fuel | Tests | Fail rate |
|---|---|---|
| Petrol | 10,311 | 9.2% |
| Diesel | 4,994 | 10.4% |
| Hybrid | 709 | 10.3% |
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2022 | 540 | 5.6% |
| 2023 | 5,333 | 9.1% |
| 2024 | 5,094 | 9.8% |
| 2025 | 5,033 | 10.4% |
What to check before buying a 2020 4 Series
The failure pattern for this year is specific enough to inspect against: tyres accounted for 7.2% of tests. Start there.
- Tyres (7.2% 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 (1.6% 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 2020 BMW 4 Seriess pass their MOT?
90.4% of the 16,014 2020 BMW 4 Series MOT tests in this dataset passed — a 9.6% fail rate.
What is the most common MOT failure on a 2020 BMW 4 Series?
Tyres, recorded in 7.2% of tests, followed by lighting & signalling (1.6%).
Does the 2020 4 Series get worse with mileage?
Its MOT fail rate rises from 7.7% in the 0-30k band to 19.1% in the 90-120k band.
Methodology & source. Based on 16,014 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.