2020 BMW Z4 — MOT failures & pass rate
The 2020 BMW Z4 passed 92.6% of its 5,056 recorded MOT tests. That is effectively the same as coupes & convertibles of a similar age (8.2% 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 5.8% of tests against 1.3% for the next-worst category.
At component level the recurring items are headlamp aim, tread depth and registration plates — headlamp aim alone was recorded 81 times.
Mileage is the strongest signal on the record: 6.6% of 0-30k cars fail, rising to 12.9% once past 60-90k.
Tyres is the most common advisory, noted on 20.4% of tests — work that passed today but is likely due soon.
The trend is worsening — 4.5% of tests failed in 2022 against 7.5% in 2025, the usual pattern as a fleet ages.
How it compares
Top failure categories
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Tyres | 5.8% | 293 |
| 2 | Lighting & signalling | 1.3% | 67 |
| 3 | Visibility | 0.6% | 29 |
| 4 | Other defects | 0.5% | 28 |
| 5 | Suspension | 0.4% | 21 |
| 6 | Road wheels | 0.2% | 12 |
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 | 81 |
| 2 | Tread depth | 49 |
| 3 | Registration plates | 44 |
| 4 | Washers | 20 |
| 5 | Wipers | 12 |
| 6 | Ball joint dust cover | 9 |
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 | 20.4% | 1,031 |
| 2 | Other defects | 3.5% | 176 |
| 3 | Brakes | 1.3% | 67 |
| 4 | Visibility | 1.3% | 67 |
| 5 | Road wheels | 1.1% | 54 |
| 6 | Suspension | 0.8% | 40 |
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 | 3,934 | 6.6% |
| 30-60k | 1,055 | 10.0% |
| 60-90k | 62 | 12.9% |
Failure rate by age
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2022 | 111 | 4.5% |
| 2023 | 1,667 | 6.2% |
| 2024 | 1,620 | 8.5% |
| 2025 | 1,645 | 7.5% |
What to check before buying a 2020 Z4
The failure pattern for this year is specific enough to inspect against: tyres accounted for 5.8% of tests. Start there.
- Tyres (5.8% 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 (1.3% of tests): Often a cheap bulb, but persistent issues can mean wiring or corrosion in the units. Typical repair: £10–£150.
- Visibility (0.6% 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 Z4s pass their MOT?
92.6% of the 5,056 2020 BMW Z4 MOT tests in this dataset passed — a 7.4% fail rate.
What is the most common MOT failure on a 2020 BMW Z4?
Tyres, recorded in 5.8% of tests, followed by lighting & signalling (1.3%).
Does the 2020 Z4 get worse with mileage?
Its MOT fail rate rises from 6.6% in the 0-30k band to 12.9% in the 60-90k band.
Methodology & source. Based on 5,056 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.