Mercedes-Benz Sls MOT pass rate & common failures
Across 11 model years and 1,701 tests, the Mercedes-Benz Sls passes its MOT 95.4% of the time. Against all cars of a similar age (22.7% fail rate), the Sls comes out 18.1pp better. Its most common failure areas are tyres, lighting & signalling and emissions & environmental.
What the MOT record shows
No single area dominates — tyres (1.5%) and lighting & signalling (1.4%) are close, so failures are spread across several systems rather than one weak point.
At component level the recurring items are headlamp aim, registration plates and malfunction indicator lamp — headlamp aim alone was recorded 26 times.
Tyres is the most common advisory, noted on 11.2% of tests — work that passed today but is likely due soon.
How it compares
By model year
Every Sls model year with a usable sample. Years with their own detailed report are linked.
| Year | Tests | Pass rate | Fail rate | Most common failure |
|---|---|---|---|---|
| 2010 | 576 | 94.1% | 5.9% | Tyres |
| 2011 | 624 | 96.2% | 3.9% | Lighting & signalling |
| 2012 | 226 | 96.0% | 4.0% | Tyres |
| 2013 | 162 | 93.8% | 6.2% | Lighting & signalling |
| 2014 | 84 | 98.8% | 1.2% | Lighting & signalling |
Most common failures (all years)
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Tyres | 1.5% | 25 |
| 2 | Lighting & signalling | 1.4% | 23 |
| 3 | Emissions & environmental | 0.9% | 16 |
| 4 | Other defects | 0.8% | 14 |
| 5 | Brakes | 0.7% | 11 |
| 6 | Visibility | 0.5% | 8 |
| 7 | Suspension | 0.2% | 3 |
| 8 | Road wheels | 0.1% | 2 |
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 | 26 |
| 2 | Registration plates | 18 |
| 3 | Malfunction indicator lamp | 13 |
| 4 | Wipers | 9 |
| 5 | Tread depth | 9 |
| 6 | Rbt (sp) | 7 |
| 7 | Headlamp | 5 |
| 8 | Switch | 4 |
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 | 11.2% | 190 |
| 2 | Brakes | 1.9% | 32 |
| 3 | Visibility | 1.9% | 32 |
| 4 | Other defects | 0.8% | 13 |
| 5 | Lighting & signalling | 0.7% | 12 |
| 6 | Emissions & environmental | 0.5% | 9 |
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 | 1,522 | 4.1% |
| 30-60k | 162 | 9.9% |
Failure rate by age
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2021 | 337 | 4.8% |
| 2022 | 343 | 3.5% |
| 2023 | 334 | 5.4% |
| 2024 | 337 | 5.6% |
| 2025 | 350 | 4.0% |
What to check before buying a Mercedes-Benz Sls
- Tyres (1.5% 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.
- Lighting & signalling (1.4% of tests): Often a cheap bulb, but persistent issues can mean wiring or corrosion in the units. Typical repair: £10–£150.
- Emissions & environmental (0.9% 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
What is the MOT pass rate for the Mercedes-Benz Sls?
95.4% of the 1,701 Mercedes-Benz Sls MOT tests in this dataset passed, a 4.6% fail rate, across model years 2010–2020.
What does the Mercedes-Benz Sls most often fail its MOT on?
Tyres, recorded in 1.5% of tests, then lighting & signalling (1.4%).
Methodology & source. Based on 1,701 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.