2015 Mercedes-Benz CLS — MOT failures & pass rate
The 2015 Mercedes-Benz CLS passed 84.8% of its 17,033 recorded MOT tests. Executive cars of a similar age fail 14.1% of the time, so this is 1.1pp worse than the group it competes with. Failures cluster in tyres, suspension and brakes.
What the MOT record shows
One area stands out: tyres, recorded in 8.7% of tests against 3.3% for the next-worst category.
At component level the recurring items are malfunction indicator lamp, tread depth and coil spring — malfunction indicator lamp alone was recorded 488 times.
Condition tracks the odometer closely. Failures run at 10.0% in the 0-30k band and 23.7% in the 150k+ band, a 13.7-point spread — more than double.
The petrol cars hold up better: 13.5% fail against 15.3% for diesel, a 1.8-point gap across 17,033 tests.
Tyres is the most common advisory, noted on 23.7% of tests — work that passed today but is likely due soon.
The trend is worsening — 14.3% of tests failed in 2021 against 16.5% in 2025, the usual pattern as a fleet ages.
How it compares
Top failure categories
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Tyres | 8.7% | 1,486 |
| 2 | Suspension | 3.3% | 567 |
| 3 | Brakes | 3.3% | 563 |
| 4 | Emissions & environmental | 3.0% | 508 |
| 5 | Lighting & signalling | 2.1% | 367 |
| 6 | Road wheels | 0.8% | 128 |
Most common specific failures
The exact components most often recorded as failures — more specific than the categories above.
| # | Failure item | Times recorded |
|---|---|---|
| 1 | Malfunction indicator lamp | 488 |
| 2 | Tread depth | 455 |
| 3 | Coil spring | 405 |
| 4 | Headlamp aim | 264 |
| 5 | Brake pads | 220 |
| 6 | Rbt (sp) | 143 |
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 | 23.7% | 4,035 |
| 2 | Brakes | 18.0% | 3,062 |
| 3 | Suspension | 8.1% | 1,381 |
| 4 | Other defects | 5.3% | 911 |
| 5 | Visibility | 2.9% | 486 |
| 6 | Road wheels | 1.5% | 260 |
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 | 703 | 10.0% |
| 30-60k | 5,481 | 13.6% |
| 60-90k | 6,473 | 16.2% |
| 90-120k | 3,048 | 15.2% |
| 120-150k | 966 | 18.3% |
| 150k+ | 359 | 23.7% |
Failure rate by age
By fuel type
| Fuel | Tests | Fail rate |
|---|---|---|
| Diesel | 16,023 | 15.3% |
| Petrol | 1,010 | 13.5% |
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2021 | 3,448 | 14.3% |
| 2022 | 3,492 | 15.6% |
| 2023 | 3,359 | 13.4% |
| 2024 | 3,385 | 16.0% |
| 2025 | 3,349 | 16.5% |
What to check before buying a 2015 CLS
The failure pattern for this year is specific enough to inspect against: tyres accounted for 8.7% of tests. Start there.
- Tyres (8.7% 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 (3.3% 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.
- Brakes (3.3% 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 2015 Mercedes-Benz CLSs pass their MOT?
84.8% of the 17,033 2015 Mercedes-Benz CLS MOT tests in this dataset passed — a 15.2% fail rate.
What is the most common MOT failure on a 2015 Mercedes-Benz CLS?
Tyres, recorded in 8.7% of tests, followed by suspension (3.3%).
Does the 2015 CLS get worse with mileage?
Its MOT fail rate rises from 10.0% in the 0-30k band to 23.7% in the 150k+ band.
Methodology & source. Based on 17,033 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.