BMW M340i — MOT pass rate & failures
12,781 MOT tests on the BMW M340i (2019–2023) give a 90.6% pass rate. That is 8.0 percentage points better than the 17.4% fail rate across all BMW 3 Series versions, so the M340i is a stronger pick within the range. Failures concentrate in tyres, lighting & signalling and suspension.
What the MOT record shows
At component level the recurring items are tread depth, headlamp aim and registration plates — tread depth alone was recorded 166 times.
Mileage matters less than usual here: the M340i fails 8.9% of the time in the 0-30k band and 6.7% at 90-120k, a spread of only 2.2 points.
Tyres is the most common advisory, noted on 11.5% of tests — work that passed today but is likely due soon.
How it compares
By model year
| Year | Tests | Pass rate | Fail rate |
|---|---|---|---|
| 2019 | 2,350 | 90.4% | 9.6% |
| 2020 | 4,763 | 90.0% | 10.0% |
| 2021 | 4,129 | 91.3% | 8.7% |
| 2022 | 1,473 | 90.6% | 9.4% |
| 2023 | 66 | 93.9% | 6.1% |
Top failure categories
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Tyres | 7.4% | 948 |
| 2 | Lighting & signalling | 1.2% | 153 |
| 3 | Suspension | 0.7% | 85 |
| 4 | Visibility | 0.5% | 68 |
| 5 | Other defects | 0.5% | 61 |
| 6 | Brakes | 0.5% | 60 |
| 7 | Road wheels | 0.3% | 40 |
| 8 | Emissions & environmental | 0.2% | 27 |
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 | 166 |
| 2 | Headlamp aim | 163 |
| 3 | Registration plates | 92 |
| 4 | Ball joint | 78 |
| 5 | Washers | 41 |
| 6 | Brake pads | 33 |
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 | 11.5% | 1,464 |
| 2 | Other defects | 3.9% | 495 |
| 3 | Brakes | 2.5% | 318 |
| 4 | Visibility | 1.9% | 240 |
| 5 | Suspension | 0.8% | 104 |
| 6 | Emissions & environmental | 0.7% | 94 |
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 | 6,467 | 8.9% |
| 30-60k | 5,721 | 9.8% |
| 60-90k | 535 | 11.8% |
| 90-120k | 45 | 6.7% |
Failure rate by age
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2022 | 707 | 9.3% |
| 2023 | 2,304 | 10.3% |
| 2024 | 4,253 | 9.5% |
| 2025 | 5,505 | 9.0% |
What to check before buying a BMW M340i
Focus on the areas it most often fails on — and remember MOT data covers testable defects only, not engine or gearbox health.
- Tyres (7.4% 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 (1.2% of tests): Often a cheap bulb, but persistent issues can mean wiring or corrosion in the units. Typical repair: £10–£150.
- Suspension (0.7% of tests): Worn drop links, bushes, springs or shocks — listen for knocks over bumps and check for uneven tyre wear. Typical repair: £150–£450 per corner.
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 reliable is the BMW M340i at MOT time?
90.6% of the 12,781 BMW M340i MOT tests in this dataset passed — a 9.4% fail rate, better than the 17.4% average across all 3 Series versions.
What is the most common MOT failure on a BMW M340i?
Tyres, recorded in 7.4% of tests, followed by lighting & signalling (1.2%).
Does the M340i get worse with mileage?
Its MOT fail rate rises from 8.9% in the 0-30k band to 6.7% in the 90-120k band.
Methodology & source. Based on 12,781 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.