2015 Mercedes-Benz S-Class — MOT failures & pass rate
12,481 MOT tests on the 2015 Mercedes-Benz S-Class are in this dataset, and 89.5% of them passed. Executive cars of a similar age fail 14.0% of the time, so this is 3.5pp better than the group it competes with. Failures cluster in tyres, suspension and visibility.
What the MOT record shows
No single area dominates — tyres (4.8%) and suspension (2.9%) are close, so failures are spread across several systems rather than one weak point.
At component level the recurring items are ball joint, tread depth and washers — ball joint alone was recorded 369 times.
Mileage matters less than usual here: the 2015 S-Class fails 6.2% of the time in the 0-30k band and 10.0% at 150k+, a spread of only 3.8 points.
The petrol cars hold up better: 9.2% fail against 11.6% for hybrid, a 2.4-point gap across 3,688 tests.
Tyres is the most common advisory, noted on 18.9% of tests — work that passed today but is likely due soon.
How it compares
Top failure categories
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Tyres | 4.8% | 596 |
| 2 | Suspension | 2.9% | 367 |
| 3 | Visibility | 1.6% | 194 |
| 4 | Lighting & signalling | 1.5% | 188 |
| 5 | Brakes | 1.4% | 169 |
| 6 | Emissions & environmental | 1.2% | 148 |
Most common specific failures
The exact components most often recorded as failures — more specific than the categories above.
| # | Failure item | Times recorded |
|---|---|---|
| 1 | Ball joint | 369 |
| 2 | Tread depth | 339 |
| 3 | Washers | 151 |
| 4 | Malfunction indicator lamp | 141 |
| 5 | Brake pads | 140 |
| 6 | Headlamp aim | 97 |
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 | 18.9% | 2,358 |
| 2 | Brakes | 11.7% | 1,463 |
| 3 | Suspension | 7.2% | 898 |
| 4 | Visibility | 3.3% | 416 |
| 5 | Other defects | 3.0% | 379 |
| 6 | Emissions & environmental | 1.4% | 176 |
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 | 1,329 | 6.2% |
| 30-60k | 3,868 | 11.0% |
| 60-90k | 3,239 | 12.0% |
| 90-120k | 1,819 | 10.4% |
| 120-150k | 990 | 9.7% |
| 150k+ | 1,234 | 10.0% |
Failure rate by age
By fuel type
| Fuel | Tests | Fail rate |
|---|---|---|
| Diesel | 8,793 | 10.6% |
| Petrol | 2,470 | 9.2% |
| Hybrid | 1,218 | 11.6% |
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2021 | 2,698 | 10.4% |
| 2022 | 2,587 | 10.5% |
| 2023 | 2,490 | 10.5% |
| 2024 | 2,386 | 10.8% |
| 2025 | 2,320 | 10.0% |
What to check before buying a 2015 S-Class
The failure pattern for this year is specific enough to inspect against: tyres accounted for 4.8% of tests. Start there.
- Tyres (4.8% 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 (2.9% 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.
- Visibility (1.6% 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.
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 S-Classs pass their MOT?
89.5% of the 12,481 2015 Mercedes-Benz S-Class MOT tests in this dataset passed — a 10.5% fail rate.
What is the most common MOT failure on a 2015 Mercedes-Benz S-Class?
Tyres, recorded in 4.8% of tests, followed by suspension (2.9%).
Does the 2015 S-Class get worse with mileage?
Its MOT fail rate rises from 6.2% in the 0-30k band to 10.0% in the 150k+ band.
Methodology & source. Based on 12,481 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.