1992 Mercedes-Benz Sl — MOT failures & pass rate
Across 692 MOT tests, the 1992 Mercedes-Benz Sl recorded an 88.9% pass rate. That is 8.0 percentage points better than coupes & convertibles of a similar age, which fail at 19.1%. Failures cluster in lighting & signalling, visibility and brakes.
What the MOT record shows
One area stands out: lighting & signalling, recorded in 8.2% of tests against 3.2% for the next-worst category.
At component level the recurring items are position lamp, wipers and headlamp aim — position lamp alone was recorded 25 times.
Condition tracks the odometer closely. Failures run at 4.0% in the 0-30k band and 14.3% in the 150k+ band, a 10.3-point spread — more than double.
Brakes is the most common advisory, noted on 22.4% of tests — work that passed today but is likely due soon.
How it compares
Top failure categories
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Lighting & signalling | 8.2% | 57 |
| 2 | Visibility | 3.2% | 22 |
| 3 | Brakes | 2.8% | 19 |
| 4 | Tyres | 2.2% | 15 |
| 5 | Emissions & environmental | 2.0% | 14 |
| 6 | Steering | 1.7% | 12 |
Most common specific failures
The exact components most often recorded as failures — more specific than the categories above.
| # | Failure item | Times recorded |
|---|---|---|
| 1 | Position lamp | 25 |
| 2 | Wipers | 16 |
| 3 | Headlamp aim | 12 |
| 4 | Flexible brake hoses | 12 |
| 5 | Rigid brake pipes | 12 |
| 6 | Rear fog lamp | 11 |
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 | 22.4% | 155 |
| 2 | Suspension | 19.8% | 137 |
| 3 | Tyres | 14.2% | 98 |
| 4 | Emissions & environmental | 12.1% | 84 |
| 5 | Steering | 6.8% | 47 |
| 6 | Body, structure & corrosion | 5.1% | 35 |
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 | 50 | 4.0% |
| 30-60k | 101 | 11.9% |
| 60-90k | 210 | 9.5% |
| 90-120k | 184 | 13.6% |
| 120-150k | 84 | 10.7% |
| 150k+ | 63 | 14.3% |
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2021 | 140 | 11.4% |
| 2022 | 163 | 9.8% |
| 2023 | 133 | 10.5% |
| 2024 | 130 | 12.3% |
| 2025 | 126 | 11.9% |
What to check before buying a 1992 Sl
The failure pattern for this year is specific enough to inspect against: lighting & signalling accounted for 8.2% of tests. Start there.
- Lighting & signalling (8.2% of tests): Often a cheap bulb, but persistent issues can mean wiring or corrosion in the units. Typical repair: £10–£150.
- Visibility (3.2% of tests): Wipers, washers, mirrors and screen damage — usually inexpensive, but check for chips in the driver's line of sight. Typical repair: £15–£150.
- Brakes (2.8% 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.
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 1992 Mercedes-Benz Sls pass their MOT?
88.9% of the 692 1992 Mercedes-Benz Sl MOT tests in this dataset passed — a 11.1% fail rate.
What is the most common MOT failure on a 1992 Mercedes-Benz Sl?
Lighting & signalling, recorded in 8.2% of tests, followed by visibility (3.2%).
Does the 1992 Sl get worse with mileage?
Its MOT fail rate rises from 4.0% in the 0-30k band to 14.3% in the 150k+ band.
Methodology & source. Based on 692 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.