Mercedes-Benz SLK: what fails at MOT
82,000 MOT tests on the Mercedes-Benz SLK in 2024, counted. 23.6% failed at the first attempt.
The short answer
23.6% of Mercedes-Benz SLK tests failed at the first attempt. Cars of the same ages averaged 35%, so the SLK does better than most cars its age.
It fails most often on suspension (7.3% of tests), tyres (3.6% of tests) and brakes (3.3% 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 |
|---|---|---|---|---|
| 2016 | 2,121 | 14.9% | 21.3% | 39,100 27,500 to 53,800 |
| 2015 | 9,082 | 15.9% | 24.4% | 45,600 32,400 to 59,500 |
| 2014 | 9,094 | 17.8% | 27.7% | 52,200 37,400 to 68,100 |
| 2013 | 8,579 | 20.3% | 30.6% | 58,600 44,700 to 75,700 |
| 2012 | 10,602 | 20.9% | 33.4% | 60,600 45,000 to 78,100 |
| 2011 | 4,534 | 19.3% | 36.1% | 57,800 43,300 to 75,000 |
| 2010 | 3,405 | 27.9% | 38.6% | 62,200 46,700 to 79,500 |
| 2009 | 4,107 | 27.8% | 39.8% | 68,200 50,700 to 86,700 |
| 2008 | 5,285 | 27.1% | 41.5% | 72,900 54,900 to 91,000 |
| 2007 | 5,937 | 29.5% | 41.5% | 73,200 55,900 to 94,300 |
| 2006 | 6,068 | 29.7% | 42.4% | 77,700 57,600 to 99,500 |
| 2005 | 7,881 | 30.0% | 42.2% | 80,000 60,000 to 100,900 |
| 2004 | 4,903 | 32.3% | 42.3% | 82,600 60,900 to 104,300 |
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 SLK tests with at least one failure in each part of the MOT, beside what cars of the same ages average.
| Part of the test | SLK | Cars its age |
|---|---|---|
| Suspension | 7.3% | 8.9% |
| Tyres | 3.6% | 4.7% |
| Brakes Less than most | 3.3% | 6.4% |
| Lights and electrics Less than most | 3.3% | 10.7% |
| Wipers, washers and windscreen Less than most | 1.3% | 3.8% |
| Exhaust and emissions Less than most | 1.3% | 3.1% |
| Seat belts and airbags | 0.7% | 1.0% |
| Body and structure Less than most | 0.6% | 3.7% |
The parts that fail most
- Coil spring3.0%
- Tyre2.5%
- Ball joint2.0%
- Tyre tread1.2%
- Headlamp aim1.2%
- Brake pipes0.9%
- Engine warning light0.9%
- Headlamp0.8%
- Ball joint dust cover0.8%
- Washers0.7%
Share of tests with a failure on that part.
The most common failures
- Coil spring: fractured or broken3.0%
- Ball joint: excessively worn1.9%
- Tyre tread: below requirements of 1.6mm1.2%
- Tyre: has ply or cords exposed1.0%
- Engine warning light: inoperative or indicates a malfunction0.9%
- Brake pipes: excessively corroded0.8%
- Ball joint dust cover: no longer prevents the ingress of dirt0.7%
- Suspension pins and bushes: pin or bush excessively worn0.7%
- Tyre: has a cut in excess of the requirements deep enough to reach the ply or cords0.7%
- Airbag warning light: warning lamp indicates a fault0.7%
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 edge9.1%
- Brake pipes: corroded, covered in grease or other material5.5%
- Brake discs: worn, pitted or scored, but not seriously weakened4.5%
- Tyre: slightly damaged/cracking or perishing4.2%
- Suspension pins and bushes: pin or bush worn but not resulting in excessive movement2.8%
- Brake pads: wearing thin2.5%
- Wheel bearings: has slight play2.0%
- Ball joint: has slight play1.4%
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
- “Have any suspension parts been replaced, such as springs, ball joints or bushes, and can I see the invoice?”
- “How much tread is left on each tyre, and how old are they?”
- “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 SLK's own MOT record
Looking at a SLK? Type its registration to 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.