Mercedes-Benz SL MOT pass rate and common problems
88.1% of 47,078 Mercedes-Benz SL MOT tests pass.
The SL has a pass rate of 88.1%, a little higher than the average across all Mercedes-Benz models (83.5%).
The Mercedes-Benz SL passes its MOT 88.1% of the time — well above the national average for cars, which sits at 79.2%.
Own this Mercedes-Benz SL?
This is the average across every Mercedes-Benz SL in the dataset. Look up your own registration for its actual MOT history, and a free place to keep its maintenance records.
Have service invoices? Upload and keep them with your car’s history →
How to check and keep your Mercedes-Benz’s service history →
Pass rate by vehicle age
Pass rate declines noticeably with age, from 95.0% at 3–6 years to 86.3% at 15+ years.
| Vehicle age | Pass rate | Tests | Average mileage |
|---|---|---|---|
| 0–3 years | too few tests (4) | 4 | no reading |
| 3–6 years | 95.0% | 1,369 | 21,906 miles |
| 6–10 years | 93.5% | 7,644 | 36,626 miles |
| 10–15 years | 88.6% | 6,649 | 51,665 miles |
| 15+ years | 86.3% | 31,412 | 80,621 miles |
Common MOT failure reasons for the Mercedes-Benz SL
The most common reason the Mercedes-Benz SL fails its MOT is lamps, reflectors and electrical equipment — present in 37.9% of failed tests, most often logged as "Not working".
| Category | Share of failed tests | Example |
|---|---|---|
| Lamps, reflectors and electrical equipment | 37.9% | Not working |
| Suspension | 28.9% | Ball joint dust cover no longer prevents the ingress of dirt |
| Brakes | 27.3% | Excessively corroded |
| Tyres | 24.6% | Has ply or cords exposed |
| Noise, emissions and leaks | 13.0% | Inoperative or indicates a malfunction |
| Visibility | 12.3% | Does not clear the windscreen effectively |
| Body, chassis, structure | 4.9% | Has a major leak of exhaust gases |
| Steering | 4.0% | Ball joint has excessive play |
| Identification of the vehicle | 3.9% | Does not conform to the specified requirements |
| Seat belts and supplementary restraint systems | 3.0% | Warning lamp indicates a fault |
Buying a used Mercedes-Benz SL: what to check
These checks follow the Mercedes-Benz SL’s own MOT record: the areas it fails on most often, and how that changes as the car gets older. None of them replaces a mechanic’s inspection, but they tell you where to look first.
The biggest drop in pass rate for the Mercedes-Benz SL comes between 6–10 years and 10–15 years old, from 93.5% to 88.6%. If you are looking at one in or just past that range, read its MOT history closely.
By mileage, the steepest fall is from 30,000–60,000 mi to 60,000–90,000 mi: 91.1% down to 85.3%. Mileage matters as well as age, so compare the car’s recorded mileages with its year.
1. Lights and electrics
Recorded in 37.9% of failed Mercedes-Benz SL MOTs. 7.7% of tests at 15+ years failed on lights and electrics, against 1.0% at 3–6 years.
Walk round with the lights on: headlights (dipped and main), indicators, brake lights, fog light and number-plate lamp. Check the dashboard warning lights come on with the ignition, then go out once the engine starts.
2. Suspension
Recorded in 28.9% of failed Mercedes-Benz SL MOTs. 5.4% of tests at 15+ years failed on suspension, against 0.6% at 3–6 years.
Listen for knocks over bumps and speed humps, and check the car sits level. Push down on each corner: it should settle rather than keep bouncing.
3. Brakes
Recorded in 27.3% of failed Mercedes-Benz SL MOTs. Rare on young cars, but 5.2% of tests at 15+ years failed on brakes.
On the test drive, the car should stop straight without pulling or juddering, and the handbrake should hold it on a slope. Look through the wheels for scored or heavily lipped discs.
4. Tyres
Recorded in 24.6% of failed Mercedes-Benz SL MOTs.
Check tread depth across the whole width of every tyre, including the inner edge. Uneven wear can point to alignment or suspension problems. Look for cuts and bulges in the sidewalls.
5. Exhaust, emissions and leaks
Recorded in 13.0% of failed Mercedes-Benz SL MOTs. Rare on young cars, but 2.3% of tests at 15+ years failed on exhaust, emissions and leaks.
Look under the car for fresh oil or coolant, and listen for blows or rattles from the exhaust. Watch for smoke from the tailpipe when the engine starts and when you accelerate.
Check the car’s own MOT history. Averages describe the model, not the car in front of you. Look up its registration for past failures, advisories that were never fixed, and gaps or dips in the recorded mileage.
Ask for the service history. Invoices show what was done and when; a stamp alone shows less. See how to check Mercedes-Benz service history and what a service history check can tell you.
Related Mercedes-Benz models
- Mercedes-Benz ML — 80.7% pass rate
- Mercedes-Benz S-Class — 88.9% pass rate
- Mercedes-Benz CLK — 71.1% pass rate
- Mercedes-Benz CLS — 81.0% pass rate
- Mercedes-Benz Sprinter — 76.9% pass rate
- Mercedes-Benz Citan — 72.0% pass rate
Frequently asked questions
- What is the MOT pass rate for the Mercedes-Benz SL?
- 88.1% of Mercedes-Benz SL MOT tests pass, based on 47,078 tests in the DVSA anonymised MOT tests and results dataset.
- What are the most common MOT failures for the Mercedes-Benz SL?
- The most common reason the Mercedes-Benz SL fails its MOT is lamps, reflectors and electrical equipment — present in 37.9% of failed tests, most often logged as "Not working".
- What are the common problems with the Mercedes-Benz SL?
- Going by its MOT results, the most common problem areas on the Mercedes-Benz SL are lights and electrics; suspension; brakes. 7.7% of tests at 15+ years failed on lights and electrics, against 1.0% at 3–6 years.
- What should I check when buying a used Mercedes-Benz SL?
- Start with the areas it most often fails its MOT on: lights and electrics; suspension; brakes; tyres; exhaust, emissions and leaks. Then check the specific car's MOT history by registration for failures, advisories and mileage, and ask the seller for service invoices.
- Does this show the Mercedes-Benz SL's service history?
- No — this is MOT test data, which covers roadworthiness, not servicing. A service history is a separate record of maintenance work, which a specific car only has if its owner has kept it. See the Mercedes-Benz service history guide for how to check and keep one.