2015 Mercedes-Benz CLA — MOT failures & pass rate
40,695 MOT tests on the 2015 Mercedes-Benz CLA are in this dataset, and 84.0% of them passed. That is effectively the same as small family cars of a similar age (15.6% fail rate), so the MOT record here is unremarkable in either direction. Failures cluster in tyres, suspension and lighting & signalling.
What the MOT record shows
One area stands out: tyres, recorded in 8.2% of tests against 4.5% for the next-worst category.
At component level the recurring items are tread depth, coil spring and brake pads — tread depth alone was recorded 1,294 times.
Condition tracks the odometer closely. Failures run at 8.8% in the 0-30k band and 19.3% in the 150k+ band, a 10.5-point spread — more than double.
Fuel type barely separates them — petrol fails 15.2% of the time against 16.4% for diesel.
Tyres is the most common advisory, noted on 26.4% of tests — work that passed today but is likely due soon.
The trend is worsening — 13.5% of tests failed in 2021 against 18.7% in 2025, the usual pattern as a fleet ages.
How it compares
Top failure categories
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Tyres | 8.2% | 3,351 |
| 2 | Suspension | 4.5% | 1,846 |
| 3 | Lighting & signalling | 3.2% | 1,294 |
| 4 | Brakes | 2.9% | 1,168 |
| 5 | Visibility | 2.6% | 1,060 |
| 6 | Emissions & environmental | 2.3% | 922 |
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 | 1,294 |
| 2 | Coil spring | 1,210 |
| 3 | Brake pads | 896 |
| 4 | Malfunction indicator lamp | 844 |
| 5 | Washers | 760 |
| 6 | Headlamp aim | 736 |
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 | 26.4% | 10,754 |
| 2 | Brakes | 19.2% | 7,821 |
| 3 | Other defects | 6.1% | 2,486 |
| 4 | Suspension | 5.6% | 2,290 |
| 5 | Visibility | 3.3% | 1,323 |
| 6 | Road wheels | 1.8% | 720 |
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 | 1,480 | 8.8% |
| 30-60k | 12,575 | 12.9% |
| 60-90k | 15,902 | 16.8% |
| 90-120k | 7,489 | 18.8% |
| 120-150k | 2,411 | 20.7% |
| 150k+ | 829 | 19.3% |
Failure rate by age
By fuel type
| Fuel | Tests | Fail rate |
|---|---|---|
| Diesel | 26,259 | 16.4% |
| Petrol | 14,436 | 15.2% |
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2021 | 8,087 | 13.5% |
| 2022 | 8,143 | 14.6% |
| 2023 | 8,159 | 16.1% |
| 2024 | 8,193 | 16.9% |
| 2025 | 8,113 | 18.7% |
What to check before buying a 2015 CLA
The failure pattern for this year is specific enough to inspect against: tyres accounted for 8.2% of tests. Start there.
- Tyres (8.2% 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.
- Suspension (4.5% 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.
- Lighting & signalling (3.2% 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 2015 Mercedes-Benz CLAs pass their MOT?
84.0% of the 40,695 2015 Mercedes-Benz CLA MOT tests in this dataset passed — a 16.0% fail rate.
What is the most common MOT failure on a 2015 Mercedes-Benz CLA?
Tyres, recorded in 8.2% of tests, followed by suspension (4.5%).
Does the 2015 CLA get worse with mileage?
Its MOT fail rate rises from 8.8% in the 0-30k band to 19.3% in the 150k+ band.
Methodology & source. Based on 40,695 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.