2013 Mercedes-Benz SLK — MOT failures & pass rate
The 2013 Mercedes-Benz SLK passed 82.7% of its 27,434 recorded MOT tests. Against coupes & convertibles of a similar age (14.7% fail rate), the 2013 SLK comes out 2.7pp worse. Failures cluster in suspension, tyres and brakes.
What the MOT record shows
No single area dominates — suspension (7.8%) and tyres (7.2%) are close, so failures are spread across several systems rather than one weak point.
At component level the recurring items are coil spring, tread depth and linkage ball joint dust cover — coil spring alone was recorded 1,209 times.
Condition tracks the odometer closely. Failures run at 9.6% in the 0-30k band and 25.2% in the 150k+ band, a 15.7-point spread — more than double.
The petrol cars hold up better: 14.2% fail against 18.5% for diesel, a 4.3-point gap across 27,434 tests.
Tyres is the most common advisory, noted on 24.5% of tests — work that passed today but is likely due soon.
The trend is worsening — 14.5% of tests failed in 2021 against 19.2% in 2025, the usual pattern as a fleet ages.
How it compares
Top failure categories
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Suspension | 7.8% | 2,151 |
| 2 | Tyres | 7.2% | 1,963 |
| 3 | Brakes | 3.4% | 943 |
| 4 | Lighting & signalling | 3.2% | 888 |
| 5 | Visibility | 1.5% | 410 |
| 6 | Emissions & environmental | 0.7% | 202 |
Most common specific failures
The exact components most often recorded as failures — more specific than the categories above.
| # | Failure item | Times recorded |
|---|---|---|
| 1 | Coil spring | 1,209 |
| 2 | Tread depth | 913 |
| 3 | Linkage ball joint dust cover | 603 |
| 4 | Headlamp aim | 557 |
| 5 | Ball joint dust cover | 405 |
| 6 | Anti-lock braking system | 370 |
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 | 24.5% | 6,727 |
| 2 | Brakes | 18.5% | 5,068 |
| 3 | Suspension | 13.4% | 3,682 |
| 4 | Other defects | 3.1% | 858 |
| 5 | Visibility | 2.6% | 728 |
| 6 | Lighting & signalling | 1.6% | 446 |
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 | 2,786 | 9.6% |
| 30-60k | 12,851 | 14.9% |
| 60-90k | 8,909 | 21.0% |
| 90-120k | 2,324 | 24.3% |
| 120-150k | 460 | 25.7% |
| 150k+ | 103 | 25.2% |
Failure rate by age
By fuel type
| Fuel | Tests | Fail rate |
|---|---|---|
| Diesel | 20,051 | 18.5% |
| Petrol | 7,383 | 14.2% |
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2021 | 5,436 | 14.5% |
| 2022 | 5,488 | 16.5% |
| 2023 | 5,555 | 17.6% |
| 2024 | 5,495 | 19.0% |
| 2025 | 5,460 | 19.2% |
What to check before buying a 2013 SLK
The failure pattern for this year is specific enough to inspect against: suspension accounted for 7.8% of tests. Start there.
- Suspension (7.8% 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.
- Tyres (7.2% 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.
- Brakes (3.4% 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 2013 Mercedes-Benz SLKs pass their MOT?
82.7% of the 27,434 2013 Mercedes-Benz SLK MOT tests in this dataset passed — a 17.3% fail rate.
What is the most common MOT failure on a 2013 Mercedes-Benz SLK?
Suspension, recorded in 7.8% of tests, followed by tyres (7.2%).
Does the 2013 SLK get worse with mileage?
Its MOT fail rate rises from 9.6% in the 0-30k band to 25.2% in the 150k+ band.
Methodology & source. Based on 27,434 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.