2011 Mercedes-Benz Sl — MOT failures & pass rate
The 2011 Mercedes-Benz Sl passed 88.7% of its 1,470 recorded MOT tests. Against coupes & convertibles of a similar age (17.8% fail rate), the 2011 Sl comes out 6.5pp better. Failures cluster in tyres, lighting & signalling and suspension.
What the MOT record shows
No single area dominates — tyres (5.1%) and lighting & signalling (3.7%) are close, so failures are spread across several systems rather than one weak point.
At component level the recurring items are coil spring, individual direction indicators and headlamp aim — coil spring alone was recorded 34 times.
Condition tracks the odometer closely. Failures run at 6.0% in the 0-30k band and 18.8% in the 90-120k band, a 12.9-point spread — more than double.
Advisories point at the next bill rather than this one: tyres was flagged on 19.2% of tests without failing them.
The trend is worsening — 10.2% of tests failed in 2021 against 11.9% in 2025, the usual pattern as a fleet ages.
How it compares
Top failure categories
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Tyres | 5.1% | 75 |
| 2 | Lighting & signalling | 3.7% | 55 |
| 3 | Suspension | 3.7% | 54 |
| 4 | Brakes | 1.6% | 24 |
| 5 | Visibility | 0.8% | 11 |
| 6 | Emissions & environmental | 0.8% | 11 |
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 | 34 |
| 2 | Individual direction indicators | 23 |
| 3 | Headlamp aim | 18 |
| 4 | Side repeaters | 15 |
| 5 | Tread depth | 13 |
| 6 | Registration plates | 12 |
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 | 19.2% | 282 |
| 2 | Brakes | 14.3% | 210 |
| 3 | Suspension | 8.5% | 125 |
| 4 | Lighting & signalling | 4.8% | 71 |
| 5 | Other defects | 3.1% | 46 |
| 6 | Visibility | 1.8% | 26 |
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 | 302 | 6.0% |
| 30-60k | 777 | 10.4% |
| 60-90k | 302 | 15.6% |
| 90-120k | 69 | 18.8% |
Failure rate by age
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2021 | 314 | 10.2% |
| 2022 | 302 | 11.6% |
| 2023 | 293 | 12.3% |
| 2024 | 283 | 10.6% |
| 2025 | 278 | 11.9% |
What to check before buying a 2011 Sl
On a 2011 Sl, tyres is what the MOT record says goes wrong most — it appeared in 5.1% of tests. Check these areas before you commit.
- Tyres (5.1% 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.
- Lighting & signalling (3.7% of tests): Often a cheap bulb, but persistent issues can mean wiring or corrosion in the units. Typical repair: £10–£150.
- Suspension (3.7% 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.
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 2011 Mercedes-Benz Sls pass their MOT?
88.7% of the 1,470 2011 Mercedes-Benz Sl MOT tests in this dataset passed — a 11.3% fail rate.
What is the most common MOT failure on a 2011 Mercedes-Benz Sl?
Tyres, recorded in 5.1% of tests, followed by lighting & signalling (3.7%).
Does the 2011 Sl get worse with mileage?
Its MOT fail rate rises from 6.0% in the 0-30k band to 18.8% in the 90-120k band.
Methodology & source. Based on 1,470 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.