83.9%
Mercedes-Benz S-Class pass rate
Used Mercedes-Benz S-Class buying guide
In 2025, Mercedes-Benz S-Class cars passed 83.9% of 26,391 initial MOT tests, 11.6 points above the 72.3% UK average. Here is where it fails and what to check before you buy.
Looking at a specific S-Class? Check its finance, write-off, stolen, mileage and keeper history. £15, no account needed.
Mercedes-Benz S-Class MOT record in brief
Initial MOT tests in 2025, retests excluded.
72.3%
UK average, all cars
+11.6
percentage points above average
Ranked on pass rate the S-Class sits 140th of 575 models in the data. Mercedes-Benz as a brand averaged 77.1%, so this model runs 6.9 points ahead of its own brand. Mercedes-Benz S-Class cars aged 3 to 5 years passed 91.2% of MOT tests in 2025; for examples aged 11 years and over that fell to 77.3%.
A pass rate is not a reliability score. The full Mercedes-Benz S-Class MOT record has the pass rate by age, every common failure and how the S-Class compares with similar cars.
S-Class fuel types
Diesel made up 65.8% of Mercedes-Benz S-Class MOT tests in 2025, against 39.3% across all models in this data. Most used examples you look at will be diesels.
Where the S-Class fails its MOT
Where Mercedes-Benz S-Class cars that failed their 2025 MOT were marked down, as a share of all recorded failure items.
The specific items testers recorded most often were ball joint excessively worn (9.7%), tread depth below requirements of 1.6mm (6.7%) and malfunction indicator lamp inoperative or indicates a malfunction (4.6%). See every common S-Class MOT failure.
These are DVSA failure records across every Mercedes-Benz S-Class that failed, not a claim that every S-Class has these problems.
What should you check when buying a used S-Class?
The areas above, most common first, and what an MOT tester looks at in each.
1
Suspension
Listen for knocks over bumps, check the car sits level, and look for leaking shock absorbers and split rubber gaiters. 19.8% of S-Class failure items.
2
Tyres
Check tread depth across the full width of every tyre (the legal minimum is 1.6mm), and look for cuts, bulges and uneven wear. 19.4% of S-Class failure items.
3
Brakes
Make sure the pedal feels firm, the car stops in a straight line, the handbrake holds on a slope and no brake warning light is showing. 19% of S-Class failure items.
4
Lamps, reflectors and electrical equipment
Walk round with every light on: headlights, brake lights, indicators, fog lights and the number plate lamp. Check no warning lights stay on after starting. 14.5% of S-Class failure items.
5
Noise, emissions and leaks
Listen for a blowing exhaust, watch for smoke on start-up and look under the car for oil or fluid leaks. 8.2% of S-Class failure items.
None of this replaces the car's own record. Run a free MOT history check on the registration to see every test, advisory and recorded mileage for that car.
What the MOT record doesn't tell you
Knowing Mercedes-Benz S-Class failures cluster around suspension and tyres tells you what to inspect. It tells you nothing about whether the car is safe to buy. An MOT does not show money still owed on the car, a write-off, a theft record or a clocked odometer.
Check the exact S-Class you are looking at. One £15 report, instant results, backed by a £30,000 data guarantee. More on the Mercedes-Benz history check.
- Outstanding finance
- Write-off records
- Stolen markers
- Mileage history
- Previous keepers
Other used Mercedes-Benz models
The most-tested Mercedes-Benz models in 2025, with how their MOT pass rate compares with the S-Class.
- Used Mercedes-Benz A-Class 78.4% MOT pass rate
- Used Mercedes-Benz C-Class 74.7% MOT pass rate
- Used Mercedes-Benz E-Class 77.4% MOT pass rate
- Used Mercedes-Benz GLA 83.3% MOT pass rate
- Used Mercedes-Benz Vito 67.3% MOT pass rate
- Used Mercedes-Benz GLC 86.4% MOT pass rate
See all 35 Mercedes-Benz models ranked by MOT pass rate.
Used Mercedes-Benz S-Class FAQs
Is the Mercedes-Benz S-Class reliable?
MOT data does not measure reliability. It records whether a car met the roadworthiness standard on the day of its test. What it does show is an 83.9% first-time pass rate for the Mercedes-Benz S-Class across 26,391 tests in 2025, above the 72.3% average for all cars.
Do older Mercedes-Benz S-Class cars fail their MOT more often?
Mercedes-Benz S-Class cars aged 3 to 5 years passed 91.2% of MOT tests in 2025; for examples aged 11 years and over that fell to 77.3%. On an older example, the car's own MOT history tells you more than the model average.
What should I check before buying a used Mercedes-Benz S-Class?
On the car itself, start with the areas it most often fails on: suspension, tyres and brakes. Then check the individual car's history: outstanding finance, insurance write-off records, stolen markers, mileage and previous keepers. None of these appear in the MOT record or on the V5C.
How do I check a Mercedes-Benz S-Class's history?
Enter the registration of the specific car. A Carpeep car history check reports outstanding finance, write-off category, stolen markers, mileage history, previous keepers, MOT and tax status, import and export markers and scrapped status in one £15 report.
MOT figures are aggregated from the DVSA MOT Anonymised data set for 2025 (class 4 initial tests, retests excluded), licensed under the Open Government Licence v3.0. MOT results describe roadworthiness at test, not mechanical reliability.