83%
Mercedes-Benz SL
Mercedes-Benz SL MOT pass rate and common problems
The Mercedes-Benz SL passed 83% of its initial MOT tests in 2025, 10.7 percentage points above the 72.3% UK average. The item testers recorded most often was ball joint excessively worn.
Checking a specific car? Its own results, advisories and recorded mileages are in a free MOT history check.
How the SL compares
Initial MOT tests in 2025, retests excluded. A car that failed and was repaired at the test station counts as a fail.
77.1%
Mercedes-Benz average
72.3%
UK average, all cars
The SL runs 5.9 points ahead of the Mercedes-Benz average. It is 13th of the 35 Mercedes-Benz models in the data. The average SL arrived at its test 19.7 years old with 68,104 miles recorded.
A pass rate records whether cars met the roadworthiness standard on test day. It is not a reliability score, and part of any gap reflects how old the tested cars were.
SL MOT pass rate by age
The same 2025 tests split by the car's age at test.
Mercedes-Benz SL cars aged 3 to 5 years passed 90.6% of MOT tests. For cars aged 11 years and over that fell to 81.5%, a drop of 9.1 percentage points.
| Age at test | Tests | Pass rate | vs UK average |
|---|---|---|---|
| 3 to 5 years | 510 | 90.6% | 18.3 pts above |
| 6 to 10 years | 3,300 | 89.3% | 17 pts above |
| 11 years and over | 16,981 | 81.5% | 9.2 pts above |
That is a typical decline as cars age. The UK average of 72.3% covers cars of every age, so compare like with like.
Where SL failures cluster
Every failure item recorded on Mercedes-Benz SL cars in 2025, grouped into the DVSA's test areas.
Lamps, reflectors and electrical equipment and suspension together account for 41.6% of recorded failure items. These are recorded failures across the model, not faults every car has.
The 10 most common SL MOT failures
Specific items recorded on Mercedes-Benz SL cars that failed their 2025 MOT, as a share of all recorded failure items.
Together these 10 items make up 35% of everything testers recorded against failed Mercedes-Benz SL cars. The rest is spread across many smaller items, and one failed test often records several at once.
What to look at on a SL
The recorded failures above, grouped by area, biggest first.
1
Tyres
Recorded most often: condition has a cut in excess of the requirements deep enough to reach the ply or cords, condition has ply or cords exposed, condition has a tear, caused by separation or partial failure of its structure and tread depth below requirements of 1.6mm. 13.5% of failure items.
2
Suspension
Recorded most often: ball joint excessively worn, ball joint dust cover no longer prevents the ingress of dirt and coil spring fractured or broken. 12.8% of failure items.
3
Brakes
Recorded most often: rigid brake pipes excessively corroded. 3% of failure items.
4
Visibility
Recorded most often: wipers does not clear the windscreen effectively. 3% of failure items.
The car's own MOT history matters more than any model average. A free MOT history check shows whether a specific SL has failed on these items before, or had them noted as advisories. Buying one? See the used Mercedes-Benz SL buying guide.
Already found one?
Check its finance, write-off, theft, mileage and keeper history with a £15 vehicle history report.
Mercedes-Benz SL MOT FAQs
What is the Mercedes-Benz SL MOT pass rate?
83% of Mercedes-Benz SL cars passed their initial MOT first time in 2025, from 20,859 tests. That is 10.7 percentage points above the 72.3% average for all cars, and ranks 158th of 575 models.
What does a Mercedes-Benz SL most commonly fail its MOT on?
The item testers recorded most often on Mercedes-Benz SL cars failing their 2025 MOT was ball joint excessively worn, on 4.7% of failure items. Next were ball joint dust cover no longer prevents the ingress of dirt (4.4%) and condition has a cut in excess of the requirements deep enough to reach the ply or cords (4.1%).
Which area causes the most Mercedes-Benz SL MOT failures?
Across every recorded failure item, the largest area was lamps, reflectors and electrical equipment at 21.2%, followed by suspension at 20.4%.
Do older Mercedes-Benz SL cars fail their MOT more often?
Mercedes-Benz SL cars aged 3 to 5 years passed 90.6% of MOT tests in 2025, against 81.5% for cars aged 11 years and over.
Does this mean every Mercedes-Benz SL has these problems?
No. These are the items testers recorded across every Mercedes-Benz SL that failed in 2025. They show where the model most often needs attention, not the condition of any individual car.
How do I see a specific Mercedes-Benz SL's MOT history?
Enter its registration on the free Carpeep MOT history check to see that car's own test results, failures, advisories and recorded mileages.
MOT figures are aggregated from the DVSA MOT Anonymised data set for 2025: class 4 initial tests, retests excluded, with failure items from failed tests (advisories and minor defects excluded), licensed under the Open Government Licence v3.0. MOT results describe roadworthiness at test, not mechanical reliability.