2021 BMW X4 — MOT failures & pass rate
Across 3,613 MOT tests, the 2021 BMW X4 recorded a 91.8% pass rate. Mid-size SUVs of a similar age fail at 8.1%, so the 2021 X4 sits squarely on the average. Failures cluster in tyres, visibility and lighting & signalling.
What the MOT record shows
Tyres dominates the failure mix at 5.1% of all tests — 3.4 points clear of visibility, so it is the first thing to check.
At component level the recurring items are tread depth, wipers and headlamp aim — tread depth alone was recorded 59 times.
Mileage matters less than usual here: the 2021 X4 fails 7.2% of the time in the 0-30k band and 11.1% at 60-90k, a spread of only 4.0 points.
Fuel type barely separates them — petrol fails 7.0% of the time against 8.4% for diesel.
Advisories point at the next bill rather than this one: tyres was flagged on 18.1% of tests without failing them.
The trend is worsening — 6.5% of tests failed in 2023 against 8.5% in 2025, the usual pattern as a fleet ages.
How it compares
Top failure categories
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Tyres | 5.1% | 184 |
| 2 | Visibility | 1.7% | 60 |
| 3 | Lighting & signalling | 1.6% | 56 |
| 4 | Emissions & environmental | 1.2% | 43 |
| 5 | Other defects | 0.6% | 22 |
| 6 | Brakes | 0.3% | 12 |
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 | 59 |
| 2 | Wipers | 44 |
| 3 | Headlamp aim | 42 |
| 4 | Malfunction indicator lamp | 41 |
| 5 | Registration plates | 37 |
| 6 | Washers | 26 |
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 | 18.1% | 655 |
| 2 | Other defects | 4.6% | 165 |
| 3 | Visibility | 2.6% | 95 |
| 4 | Brakes | 2.2% | 81 |
| 5 | Suspension | 1.6% | 57 |
| 6 | Lighting & signalling | 0.3% | 12 |
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 | 1,677 | 7.2% |
| 30-60k | 1,759 | 8.8% |
| 60-90k | 162 | 11.1% |
Failure rate by age
By fuel type
| Fuel | Tests | Fail rate |
|---|---|---|
| Diesel | 2,957 | 8.4% |
| Petrol | 589 | 7.0% |
| Hybrid | 67 | 10.4% |
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2023 | 92 | 6.5% |
| 2024 | 1,766 | 8.0% |
| 2025 | 1,751 | 8.5% |
What to check before buying a 2021 X4
On a 2021 X4, tyres is what the MOT record says goes wrong most — it appeared in 5.1% of tests. Check these areas before you commit.
- Tyres (5.1% 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.
- Visibility (1.7% 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.
- 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.
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 X4s pass their MOT?
91.8% of the 3,613 2021 BMW X4 MOT tests in this dataset passed — a 8.2% fail rate.
What is the most common MOT failure on a 2021 BMW X4?
Tyres, recorded in 5.1% of tests, followed by visibility (1.7%).
Does the 2021 X4 get worse with mileage?
Its MOT fail rate rises from 7.2% in the 0-30k band to 11.1% in the 60-90k band.
Methodology & source. Based on 3,613 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.