Mercedes-Benz S-Class: what fails at MOT
50,000 MOT tests on the Mercedes-Benz S-Class in 2024, counted. 12.6% failed at the first attempt.
The short answer
12.6% of Mercedes-Benz S-Class tests failed at the first attempt. Cars of the same ages averaged 25.6%, so the S-Class does better than most cars its age.
It fails most often on tyres (2.5% of tests), suspension (2% of tests) and brakes (1.8% of tests).
By year of registration
Older cars fail more, whatever the model. So each year is shown beside the figure for all cars first used that year.
| First used | Tests | Failed first time | All cars that year | Typical mileage |
|---|---|---|---|---|
| 2021 | 1,388 | 5.3% | 10.9% | 33,200 20,700 to 46,800 |
| 2020 | 1,287 | 6.4% | 11.5% | 45,000 31,100 to 61,600 |
| 2019 | 5,391 | 6.8% | 13.4% | 60,800 36,900 to 88,900 |
| 2018 | 5,713 | 6.7% | 15.6% | 64,900 39,400 to 105,400 |
| 2017 | 5,122 | 8.9% | 18.2% | 59,200 39,500 to 92,200 |
| 2016 | 5,827 | 10.7% | 21.3% | 59,500 43,400 to 88,600 |
| 2015 | 4,739 | 10.2% | 24.4% | 76,500 51,100 to 106,800 |
| 2014 | 3,330 | 9.7% | 27.7% | 84,900 58,000 to 118,000 |
| 2013 | 1,756 | 16.3% | 30.6% | 99,000 72,700 to 137,300 |
| 2012 | 2,320 | 17.7% | 33.4% | 91,500 68,500 to 122,700 |
| 2011 | 1,794 | 18.7% | 36.1% | 106,900 75,500 to 142,700 |
| 2010 | 1,629 | 18.4% | 38.6% | 106,200 83,500 to 137,200 |
| 2009 | 1,537 | 26.5% | 39.8% | 105,800 80,300 to 132,500 |
| 2008 | 1,806 | 22.1% | 41.5% | 106,600 82,600 to 133,700 |
| 2007 | 2,319 | 22.1% | 41.5% | 117,800 86,700 to 144,500 |
| 2006 | 1,919 | 19.9% | 42.4% | 108,100 81,600 to 133,400 |
| 2005 | 1,073 | 21.3% | 42.2% | 137,000 99,200 to 170,900 |
| 2004 | 981 | 24.1% | 42.3% | 119,700 86,900 to 155,500 |
Green is at least three points better than other cars that year, red at least three points worse. Typical mileage is the middle reading at the test, with the range the middle half of cars fell in.
Where it fails
The share of Mercedes-Benz S-Class tests with at least one failure in each part of the MOT, beside what cars of the same ages average.
| Part of the test | S-Class | Cars its age | |
|---|---|---|---|
| Tyres | 2.5% | 4.2% | Less than most |
| Suspension | 2.0% | 5.4% | Less than most |
| Brakes | 1.8% | 4.2% | Less than most |
| Lights and electrics | 1.5% | 6.8% | Less than most |
| Exhaust and emissions | 1.3% | 2.0% | |
| Wipers, washers and windscreen | 0.9% | 2.9% | Less than most |
| Wheels | 0.3% | 0.2% | |
| Seat belts and airbags | 0.3% | 0.6% |
The parts that fail most
- Wheel1.8%
- Ball joint1.3%
- Tyre tread1.0%
- Engine warning light0.9%
- Washers0.6%
- Brake test0.6%
- Headlamp aim0.5%
- Brake pads0.5%
- Suspension pins and bushes0.3%
- Brake pipes0.3%
Share of tests with a failure on that part.
The most common failures
- Ball joint: excessively worn1.3%
- Tyre tread: below requirements of 1.6mm1.0%
- Engine warning light: inoperative or indicates a malfunction0.9%
- Tyre: has ply or cords exposed0.6%
- Tyre: has a cut in excess of the requirements deep enough to reach the ply or cords0.5%
- Brake pads: less than 1.5 mm thick0.4%
- Brake test: efficiency below requirements0.3%
- Washers: provides insufficient washer liquid0.3%
- Suspension pins and bushes: pin or bush excessively worn0.3%
- Tyre: has a bulge, caused by separation or partial failure of its structure0.3%
What testers warn about
Advisories are things that passed this time but are wearing. They are the best guide to next year's bills.
- Tyre tread: worn close to legal limit/worn on edge7.7%
- Brake discs: worn, pitted or scored, but not seriously weakened2.9%
- Brake pads: wearing thin2.7%
- Ball joint: has slight play2.6%
- Brake pipes: corroded, covered in grease or other material2.5%
- Engine oil: leak, but not excessive1.8%
- Brake discs: worn, but not excessively1.4%
- Tyre: slightly damaged/cracking or perishing1.2%
What these figures can't tell you
An MOT is a safety and emissions test. These figures show how often the model fails that test. They say nothing about engines, gearboxes or electronics that break between tests, and how a car has been looked after matters more than its badge. The car you are looking at has its own MOT record, and that is the one to read.
Ask before you travel
- “How much tread is left on each tyre, and how old are they?”
- “Have any suspension parts been replaced, such as springs, ball joints or bushes, and can I see the invoice?”
- “When were the brake pads and discs last changed?”
- “Do all the lights work, including the number plate lights and brake lights?”
Check a Mercedes-Benz S-Class's own MOT record
Type the registration from the advert. You'll see every test that car has had, what it failed on and what it was warned about, free.
Where this comes from
DVSA anonymised MOT tests and results, 2024, published by the Driver and Vehicle Standards Agency. Contains public sector information licensed under the Open Government Licence v3.0. The counting is Hindsight's own.
First-attempt MOT tests of cars first used 2004 to 2021. A test counts as failed if it failed or only passed after a repair during the test. Retests are left out. Built on 13 November 2026.