1994 Mercedes-Benz Sl — MOT failures & pass rate
The 1994 Mercedes-Benz Sl passed 85.0% of its 2,335 recorded MOT tests. That is 4.6 percentage points better than coupes & convertibles of a similar age, which fail at 19.5%. Failures cluster in lighting & signalling, brakes and visibility.
What the MOT record shows
One area stands out: lighting & signalling, recorded in 8.6% of tests against 4.6% for the next-worst category.
At component level the recurring items are catalyst emissions, headlamp aim and wipers — catalyst emissions alone was recorded 92 times.
Condition tracks the odometer closely. Failures run at 7.4% in the 0-30k band and 23.1% in the 150k+ band, a 15.7-point spread — more than double.
Suspension is the most common advisory, noted on 23.3% 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 | 8.6% | 202 |
| 2 | Brakes | 4.6% | 107 |
| 3 | Visibility | 3.7% | 86 |
| 4 | Suspension | 3.5% | 81 |
| 5 | Emissions & environmental | 3.4% | 80 |
| 6 | Tyres | 2.9% | 68 |
Most common specific failures
The exact components most often recorded as failures — more specific than the categories above.
| # | Failure item | Times recorded |
|---|---|---|
| 1 | Catalyst emissions | 92 |
| 2 | Headlamp aim | 63 |
| 3 | Wipers | 62 |
| 4 | Position lamp | 47 |
| 5 | Rear fog lamp | 43 |
| 6 | Service brake performance | 39 |
Top advisory categories
Advisories aren't failures, but they flag work likely needed soon — useful when budgeting.
| # | Category | % of tests with advisory | Tests |
|---|---|---|---|
| 1 | Suspension | 23.3% | 545 |
| 2 | Brakes | 23.2% | 542 |
| 3 | Emissions & environmental | 17.4% | 406 |
| 4 | Tyres | 16.7% | 389 |
| 5 | Steering | 5.9% | 137 |
| 6 | Other defects | 4.8% | 111 |
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 | 95 | 7.4% |
| 30-60k | 305 | 10.5% |
| 60-90k | 692 | 11.4% |
| 90-120k | 626 | 17.3% |
| 120-150k | 424 | 18.2% |
| 150k+ | 186 | 23.1% |
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2021 | 507 | 14.6% |
| 2022 | 511 | 15.7% |
| 2023 | 467 | 16.3% |
| 2024 | 428 | 12.6% |
| 2025 | 422 | 15.4% |
What to check before buying a 1994 Sl
The failure pattern for this year is specific enough to inspect against: lighting & signalling accounted for 8.6% of tests. Start there.
- Lighting & signalling (8.6% of tests): Often a cheap bulb, but persistent issues can mean wiring or corrosion in the units. Typical repair: £10–£150.
- Brakes (4.6% 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.
- Visibility (3.7% 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.
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 1994 Mercedes-Benz Sls pass their MOT?
85.0% of the 2,335 1994 Mercedes-Benz Sl MOT tests in this dataset passed — a 14.9% fail rate.
What is the most common MOT failure on a 1994 Mercedes-Benz Sl?
Lighting & signalling, recorded in 8.6% of tests, followed by brakes (4.6%).
Does the 1994 Sl get worse with mileage?
Its MOT fail rate rises from 7.4% in the 0-30k band to 23.1% in the 150k+ band.
Methodology & source. Based on 2,335 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.