2018 BMW 3 Series — MOT failures & pass rate
139,847 MOT tests on the 2018 BMW 3 Series are in this dataset, and 90.2% of them passed. Executive cars of a similar age fail 10.8% of the time, so this is 1.0pp better than the group it competes with. Failures cluster in tyres, lighting & signalling and brakes.
What the MOT record shows
One area stands out: tyres, recorded in 6.1% of tests against 1.6% for the next-worst category.
At component level the recurring items are tread depth, brake pads and headlamp aim — tread depth alone was recorded 3,456 times.
A 150k+ example is materially riskier than a 0-30k one: 13.6% versus 6.6%.
The petrol cars hold up better: 9.1% fail against 10.9% for hybrid, a 1.8-point gap across 63,250 tests.
Tyres is the most common advisory, noted on 20.6% of tests — work that passed today but is likely due soon.
The trend is worsening — 9.0% of tests failed in 2021 against 11.2% in 2025, the usual pattern as a fleet ages.
How it compares
Top failure categories
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Tyres | 6.1% | 8,525 |
| 2 | Lighting & signalling | 1.6% | 2,279 |
| 3 | Brakes | 1.6% | 2,224 |
| 4 | Visibility | 1.4% | 1,946 |
| 5 | Suspension | 0.8% | 1,154 |
| 6 | Emissions & environmental | 0.7% | 997 |
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 | 3,456 |
| 2 | Brake pads | 1,879 |
| 3 | Headlamp aim | 1,795 |
| 4 | Washers | 1,287 |
| 5 | Malfunction indicator lamp | 873 |
| 6 | Wipers | 854 |
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 | 20.6% | 28,770 |
| 2 | Brakes | 11.3% | 15,732 |
| 3 | Other defects | 6.6% | 9,167 |
| 4 | Suspension | 4.2% | 5,841 |
| 5 | Visibility | 2.9% | 4,126 |
| 6 | Emissions & environmental | 1.5% | 2,103 |
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 | 32,596 | 6.6% |
| 30-60k | 65,762 | 9.7% |
| 60-90k | 30,754 | 12.1% |
| 90-120k | 8,138 | 13.5% |
| 120-150k | 1,906 | 14.2% |
| 150k+ | 684 | 13.6% |
Failure rate by age
By fuel type
| Fuel | Tests | Fail rate |
|---|---|---|
| Diesel | 76,595 | 9.9% |
| Petrol | 41,278 | 9.1% |
| Hybrid | 21,972 | 10.9% |
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2021 | 29,653 | 9.0% |
| 2022 | 28,430 | 8.7% |
| 2023 | 27,631 | 9.7% |
| 2024 | 27,132 | 10.6% |
| 2025 | 27,001 | 11.2% |
What to check before buying a 2018 3 Series
The failure pattern for this year is specific enough to inspect against: tyres accounted for 6.1% of tests. Start there.
- Tyres (6.1% 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.
- 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.
- Brakes (1.6% 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 2018 BMW 3 Seriess pass their MOT?
90.2% of the 139,847 2018 BMW 3 Series MOT tests in this dataset passed — a 9.8% fail rate.
What is the most common MOT failure on a 2018 BMW 3 Series?
Tyres, recorded in 6.1% of tests, followed by lighting & signalling (1.6%).
Does the 2018 3 Series get worse with mileage?
Its MOT fail rate rises from 6.6% in the 0-30k band to 13.6% in the 150k+ band.
Methodology & source. Based on 139,847 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.