In 2025, 23,678 Mercedes-Benz S-Class cars had a regular MOT in Great Britain. 83% passed first time, compared with 70% for all cars of the same ages, which makes the S-Class better than average. Adjusted for age, it ranks 4 of the 217 most-tested car models.
That comparison matters: older cars fail more often, so a raw pass rate flatters models that are mostly young. We compare each model against every car on the road at the same age.
Pass rate by age
At 5 years old, 93% of S-Classs passed first time (all cars that age: 86%). By 20 years, that figure is 72% (all cars: 58%). It beats the average car at every age with enough data, from 5 to 20 years.
Mercedes-Benz S-Class All cars of that age
| Age | Tests | S-Class passed first time | All cars | Typical mileage |
|---|---|---|---|---|
| 5 years | 253 | 93% | 86% | 56,035 |
| 6 years | 2,179 | 90% | 84% | 78,816 |
| 7 years | 2,169 | 90% | 81% | 80,626 |
| 8 years | 2,262 | 87% | 78% | 80,429 |
| 9 years | 2,626 | 86% | 75% | 82,271 |
| 10 years | 2,121 | 87% | 72% | 94,482 |
| 11 years | 1,567 | 88% | 69% | 102,382 |
| 12 years | 938 | 82% | 66% | 112,555 |
| 13 years | 1,141 | 80% | 63% | 107,998 |
| 14 years | 878 | 79% | 61% | 113,338 |
| 15 years | 767 | 78% | 59% | 112,567 |
| 16 years | 749 | 72% | 58% | 113,682 |
| 17 years | 812 | 73% | 57% | 112,981 |
| 18 years | 1,115 | 76% | 57% | 115,193 |
| 19 years | 878 | 78% | 57% | 110,404 |
| 20 years | 423 | 72% | 58% | 122,055 |
What fails most on a Mercedes-Benz S-Class
The area that lets the S-Class down most, relative to other cars, is road wheels: 1.0% of tests failed on it, 8.1 times the rate for the average car. It does comparatively well on body and structure and lights and electrics.
Share of S-Class tests failing on this area Average car
The six most common failure items
| Failure item | Area | Share of tests |
|---|---|---|
| A suspension pin, bush or joint excessively worn | Suspension | 5.0% |
| Tyre tread depth not in accordance with the requirements | Tyres | 2.6% |
| A tyre seriously damaged | Tyres | 2.0% |
| Engine MIL illuminated indicating a malfunction | Emissions and leaks | 1.8% |
| Windscreen washers not working or not providing sufficient fluid to clear the windscreen | Visibility | 1.7% |
| The aim of a headlamp is not within limits laid down in the requirements | Lights and electrics | 1.6% |
What to check when buying a used S-Class
Based on where the S-Class fails more often than other cars, these are the checks worth making before you buy:
- Road wheels: Look for damaged rims and missing wheel nuts. More
- Emissions and leaks: Look for oil and coolant leaks underneath, listen for exhaust blows on a cold start, and watch for smoke when revving. Repair guide
- Tyres: Check tread across the whole width (uneven wear hints at alignment or suspension faults), and look for cuts, bulges and mismatched brands. Repair guide
Then check the individual car: its own MOT history will show whether it follows the pattern. A car with repeated advisories in the same weak area is more likely to fail its next test.
Check a specific S-Class
Enter the registration to see its full MOT history, mileage record and reliability score, compared with these figures.
Check a S-ClassFrequently asked questions
What is the MOT pass rate for a Mercedes-Benz S-Class?
In 2025, 83% of Mercedes-Benz S-Class cars passed their MOT first time, across 23,678 tests. Cars of the same ages averaged 70%.
What do Mercedes-Benz S-Class cars most often fail their MOT on?
The most common failure items were: a suspension pin, bush or joint excessively worn (5.0% of tests); tyre tread depth not in accordance with the requirements (2.6% of tests); a tyre seriously damaged (2.0% of tests).
Other Mercedes-Benz models
Mercedes-Benz C-Class (74%), Mercedes-Benz A-Class (77%), Mercedes-Benz E-Class (77%), Mercedes-Benz Vito (67%), Mercedes-Benz B-Class (72%), Mercedes-Benz Glc (85%). All Mercedes-Benz models
Source: DVSA anonymised MOT tests and results, 2025 (class 4 normal tests; first-time pass means passed with no faults fixed at the test). Contains public sector information licensed under the Open Government Licence v3.0.