Mercedes-Benz S-Class MOT pass rate and common problems
88.9% of 57,810 Mercedes-Benz S-Class MOT tests pass.
The S-Class passes its MOT 88.9% of the time — well above the average across all Mercedes-Benz models, which sits at 83.5%.
The Mercedes-Benz S-Class passes its MOT 88.9% of the time — well above the national average for cars, which sits at 79.2%.
Own this Mercedes-Benz S-Class?
This is the average across every Mercedes-Benz S-Class 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 93.9% at 0–3 years to 81.6% at 15+ years.
| Vehicle age | Pass rate | Tests | Average mileage |
|---|---|---|---|
| 0–3 years | 93.9% | 1,475 | 34,694 miles |
| 3–6 years | 94.8% | 9,930 | 66,715 miles |
| 6–10 years | 92.1% | 21,258 | 79,791 miles |
| 10–15 years | 86.6% | 10,415 | 107,029 miles |
| 15+ years | 81.6% | 14,732 | 114,247 miles |
Common MOT failure reasons for the Mercedes-Benz S-Class
The most common reason the Mercedes-Benz S-Class fails its MOT is tyres — present in 32.8% of failed tests, most often logged as "Tread depth below requirements of 1.6mm".
| Category | Share of failed tests | Example |
|---|---|---|
| Tyres | 32.8% | Tread depth below requirements of 1.6mm |
| Brakes | 32.5% | Excessively corroded |
| Suspension | 31.5% | Ball joint excessively worn |
| Lamps, reflectors and electrical equipment | 29.4% | Not working |
| Noise, emissions and leaks | 13.9% | Inoperative or indicates a malfunction |
| Visibility | 13.0% | Does not clear the windscreen effectively |
| Body, chassis, structure | 5.6% | System insecure |
| Seat belts and supplementary restraint systems | 5.0% | Warning lamp indicates a fault |
| Road Wheels | 4.2% | Fractured |
| Identification of the vehicle | 3.7% | Does not conform to the specified requirements |
Buying a used Mercedes-Benz S-Class: what to check
These checks follow the Mercedes-Benz S-Class’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 S-Class comes between 6–10 years and 10–15 years old, from 92.1% to 86.6%. If you are looking at one in or just past that range, read its MOT history closely.
By mileage, the steepest fall is from 0–30,000 mi to 30,000–60,000 mi: 95.0% down to 91.5%. Mileage matters as well as age, so compare the car’s recorded mileages with its year.
1. Tyres
Recorded in 32.8% of failed Mercedes-Benz S-Class 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.
2. Brakes
Recorded in 32.5% of failed Mercedes-Benz S-Class MOTs. Rare on young cars, but 11.1% 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.
3. Suspension
Recorded in 31.5% of failed Mercedes-Benz S-Class MOTs. Rare on young cars, but 9.1% of tests at 15+ years failed on suspension.
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.
4. Lights and electrics
Recorded in 29.4% of failed Mercedes-Benz S-Class MOTs. Rare on young cars, but 11.2% of tests at 15+ years failed on lights and electrics.
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.
5. Exhaust, emissions and leaks
Recorded in 13.9% of failed Mercedes-Benz S-Class MOTs. Rare on young cars, but 3.8% 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 SLK — 78.9% pass rate
- Mercedes-Benz Gle — 91.9% pass rate
- Mercedes-Benz ML — 80.7% pass rate
- Mercedes-Benz CLK — 71.1% pass rate
- Mercedes-Benz SL — 88.1% pass rate
- Mercedes-Benz CLS — 81.0% pass rate
Frequently asked questions
- What is the MOT pass rate for the Mercedes-Benz S-Class?
- 88.9% of Mercedes-Benz S-Class MOT tests pass, based on 57,810 tests in the DVSA anonymised MOT tests and results dataset.
- What are the most common MOT failures for the Mercedes-Benz S-Class?
- The most common reason the Mercedes-Benz S-Class fails its MOT is tyres — present in 32.8% of failed tests, most often logged as "Tread depth below requirements of 1.6mm".
- What are the common problems with the Mercedes-Benz S-Class?
- Going by its MOT results, the most common problem areas on the Mercedes-Benz S-Class are tyres; brakes; suspension.
- What should I check when buying a used Mercedes-Benz S-Class?
- Start with the areas it most often fails its MOT on: tyres; brakes; suspension; lights and electrics; 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 S-Class'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.