2006 Mercedes-Benz SLK — MOT failures & pass rate
Across 23,127 MOT tests, the 2006 Mercedes-Benz SLK recorded a 76.9% pass rate. That is 1.1 percentage points worse than coupes & convertibles of a similar age, which fail at 22.0%. Failures cluster in suspension, brakes and lighting & signalling.
What the MOT record shows
One area stands out: suspension, recorded in 13.9% of tests against 6.3% for the next-worst category.
At component level the recurring items are coil spring, ball joint and sub-frame — coil spring alone was recorded 1,322 times.
Condition tracks the odometer closely. Failures run at 9.9% in the 0-30k band and 28.6% in the 150k+ band, a 18.7-point spread — more than double.
Brakes is the most common advisory, noted on 28.4% of tests — work that passed today but is likely due soon.
How it compares
Top failure categories
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Suspension | 13.9% | 3,210 |
| 2 | Brakes | 6.3% | 1,461 |
| 3 | Lighting & signalling | 5.8% | 1,342 |
| 4 | Tyres | 4.6% | 1,055 |
| 5 | Emissions & environmental | 2.9% | 670 |
| 6 | Visibility | 2.9% | 658 |
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 | 1,322 |
| 2 | Ball joint | 1,028 |
| 3 | Sub-frame | 849 |
| 4 | Rigid brake pipes | 786 |
| 5 | Tread depth | 620 |
| 6 | SRS malfunction indicator lamp | 573 |
Top advisory categories
Advisories aren't failures, but they flag work likely needed soon — useful when budgeting.
| # | Category | % of tests with advisory | Tests |
|---|---|---|---|
| 1 | Brakes | 28.4% | 6,560 |
| 2 | Tyres | 23.8% | 5,492 |
| 3 | Suspension | 22.7% | 5,260 |
| 4 | Body, structure & corrosion | 8.3% | 1,928 |
| 5 | Other defects | 7.6% | 1,767 |
| 6 | Lighting & signalling | 7.4% | 1,721 |
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 | 1,039 | 9.9% |
| 30-60k | 5,600 | 17.5% |
| 60-90k | 8,934 | 23.8% |
| 90-120k | 5,515 | 27.3% |
| 120-150k | 1,568 | 30.9% |
| 150k+ | 440 | 28.6% |
Failure rate by age
By fuel type
| Fuel | Tests | Fail rate |
|---|---|---|
| Petrol | 23,079 | 23.1% |
| Diesel | 48 | 22.9% |
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2021 | 4,912 | 22.2% |
| 2022 | 4,804 | 23.4% |
| 2023 | 4,680 | 23.0% |
| 2024 | 4,453 | 23.1% |
| 2025 | 4,278 | 23.7% |
What to check before buying a 2006 SLK
The failure pattern for this year is specific enough to inspect against: suspension accounted for 13.9% of tests. Start there.
- Suspension (13.9% 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.
- Brakes (6.3% 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.
- Lighting & signalling (5.8% 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 2006 Mercedes-Benz SLKs pass their MOT?
76.9% of the 23,127 2006 Mercedes-Benz SLK MOT tests in this dataset passed — a 23.1% fail rate.
What is the most common MOT failure on a 2006 Mercedes-Benz SLK?
Suspension, recorded in 13.9% of tests, followed by brakes (6.3%).
Does the 2006 SLK get worse with mileage?
Its MOT fail rate rises from 9.9% in the 0-30k band to 28.6% in the 150k+ band.
Methodology & source. Based on 23,127 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.