2011 Mercedes-Benz Sls — MOT failures & pass rate
The 2011 Mercedes-Benz Sls passed 96.2% of its 624 recorded MOT tests. Against all cars of a similar age (23.2% fail rate), the 2011 Sls comes out 19.3pp better. Failures cluster in lighting & signalling, tyres and emissions & environmental.
What the MOT record shows
No single area dominates — lighting & signalling (1.8%) and tyres (1.0%) are close, so failures are spread across several systems rather than one weak point.
At component level the recurring items are headlamp aim, malfunction indicator lamp and registration plates — headlamp aim alone was recorded 11 times.
Tyres is the most common advisory, noted on 12.2% of tests — work that passed today but is likely due soon.
The trend is improving — the fail rate fell from 6.3% in 2021 to 1.6% in 2025, as the worst-kept examples leave the fleet.
How it compares
Top failure categories
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Lighting & signalling | 1.8% | 11 |
| 2 | Tyres | 1.0% | 6 |
| 3 | Emissions & environmental | 1.0% | 6 |
| 4 | Other defects | 0.8% | 5 |
| 5 | Brakes | 0.6% | 4 |
| 6 | Visibility | 0.2% | 1 |
Most common specific failures
The exact components most often recorded as failures — more specific than the categories above.
| # | Failure item | Times recorded |
|---|---|---|
| 1 | Headlamp aim | 11 |
| 2 | Malfunction indicator lamp | 6 |
| 3 | Registration plates | 5 |
| 4 | Parking brake performance | 2 |
| 5 | Tread depth | 2 |
| 6 | Wipers | 2 |
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 | 12.2% | 76 |
| 2 | Brakes | 1.9% | 12 |
| 3 | Visibility | 1.4% | 9 |
| 4 | Other defects | 0.8% | 5 |
| 5 | Suspension | 0.6% | 4 |
| 6 | Emissions & environmental | 0.5% | 3 |
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 | 578 | 3.6% |
| 30-60k | 46 | 6.5% |
Failure rate by age
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2021 | 128 | 6.3% |
| 2022 | 124 | 2.4% |
| 2023 | 123 | 3.3% |
| 2024 | 122 | 5.7% |
| 2025 | 127 | 1.6% |
What to check before buying a 2011 Sls
The failure pattern for this year is specific enough to inspect against: lighting & signalling accounted for 1.8% of tests. Start there.
- Lighting & signalling (1.8% of tests): Often a cheap bulb, but persistent issues can mean wiring or corrosion in the units. Typical repair: £10–£150.
- Tyres (1.0% 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.
- Emissions & environmental (1.0% of tests): More common on older diesels (DPF/EGR) — can be expensive; check for warning lights and smoke. Typical repair: £100–£600.
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 Slss pass their MOT?
96.2% of the 624 2011 Mercedes-Benz Sls MOT tests in this dataset passed — a 3.9% fail rate.
What is the most common MOT failure on a 2011 Mercedes-Benz Sls?
Lighting & signalling, recorded in 1.8% of tests, followed by tyres (1.0%).
Does the 2011 Sls get worse with mileage?
Its MOT fail rate rises from 3.6% in the 0-30k band to 6.5% in the 30-60k band.
Methodology & source. Based on 624 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.