2016 Mercedes-Benz SLK — MOT failures & pass rate
Across 7,027 MOT tests, the 2016 Mercedes-Benz SLK recorded an 88.7% pass rate. Coupes & convertibles of a similar age fail at 10.8%, so the 2016 SLK sits squarely on the average. Failures cluster in tyres, suspension and lighting & signalling.
What the MOT record shows
Tyres dominates the failure mix at 6.5% of all tests — 3.5 points clear of suspension, so it is the first thing to check.
At component level the recurring items are tread depth, coil spring and headlamp aim — tread depth alone was recorded 162 times.
A 90-120k example is materially riskier than a 0-30k one: 21.0% versus 7.0%.
Split by fuel, diesel examples fail 4.1pp more often than petrol ones (12.5% vs 8.4%) — worth weighing if you have a choice.
Advisories point at the next bill rather than this one: tyres was flagged on 24.6% of tests without failing them.
The trend is worsening — 8.8% of tests failed in 2021 against 14.0% in 2025, the usual pattern as a fleet ages.
How it compares
Top failure categories
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Tyres | 6.5% | 453 |
| 2 | Suspension | 3.0% | 210 |
| 3 | Lighting & signalling | 2.0% | 140 |
| 4 | Brakes | 1.4% | 95 |
| 5 | Emissions & environmental | 1.2% | 86 |
| 6 | Visibility | 0.7% | 47 |
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 | 162 |
| 2 | Coil spring | 131 |
| 3 | Headlamp aim | 111 |
| 4 | Malfunction indicator lamp | 81 |
| 5 | Ball joint | 42 |
| 6 | Registration plates | 39 |
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 | 24.6% | 1,727 |
| 2 | Brakes | 9.8% | 685 |
| 3 | Suspension | 6.3% | 442 |
| 4 | Other defects | 2.9% | 200 |
| 5 | Visibility | 2.2% | 152 |
| 6 | Road wheels | 1.5% | 108 |
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 | 2,694 | 7.0% |
| 30-60k | 3,406 | 12.6% |
| 60-90k | 790 | 18.5% |
| 90-120k | 119 | 21.0% |
Failure rate by age
By fuel type
| Fuel | Tests | Fail rate |
|---|---|---|
| Diesel | 4,968 | 12.5% |
| Petrol | 2,058 | 8.4% |
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2021 | 1,426 | 8.8% |
| 2022 | 1,366 | 9.1% |
| 2023 | 1,400 | 10.5% |
| 2024 | 1,402 | 14.0% |
| 2025 | 1,433 | 14.0% |
What to check before buying a 2016 SLK
On a 2016 SLK, tyres is what the MOT record says goes wrong most — it appeared in 6.5% of tests. Check these areas before you commit.
- Tyres (6.5% 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 (3.0% 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 (2.0% 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 2016 Mercedes-Benz SLKs pass their MOT?
88.7% of the 7,027 2016 Mercedes-Benz SLK MOT tests in this dataset passed — a 11.3% fail rate.
What is the most common MOT failure on a 2016 Mercedes-Benz SLK?
Tyres, recorded in 6.5% of tests, followed by suspension (3.0%).
Does the 2016 SLK get worse with mileage?
Its MOT fail rate rises from 7.0% in the 0-30k band to 21.0% in the 90-120k band.
Methodology & source. Based on 7,027 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.