86.5%
Mercedes-Benz GLS
Mercedes-Benz GLS MOT pass rate and common problems
The Mercedes-Benz GLS passed 86.5% of its initial MOT tests in 2025, 14.2 percentage points above the 72.3% UK average. The item testers recorded most often was tread depth below requirements of 1.6mm.
Checking a specific car? Its own results, advisories and recorded mileages are in a free MOT history check.
How the GLS 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 GLS runs 9.4 points ahead of the Mercedes-Benz average. It is 6th of the 35 Mercedes-Benz models in the data. The average GLS arrived at its test 6.1 years old with 57,855 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.
GLS MOT pass rate by age
The same 2025 tests split by the car's age at test.
Mercedes-Benz GLS cars aged 3 to 5 years passed 85.7% of MOT tests. For cars aged 6 to 10 years it rose to 87.2%, 1.5 percentage points higher.
| Age at test | Tests | Pass rate | vs UK average |
|---|---|---|---|
| 3 to 5 years | 1,098 | 85.7% | 13.4 pts above |
| 6 to 10 years | 1,702 | 87.2% | 14.9 pts above |
Older examples test at least as well as newer ones here, which usually says more about how the surviving cars have been kept than about age itself. The UK average of 72.3% covers cars of every age, so compare like with like.
Where GLS failures cluster
Every failure item recorded on Mercedes-Benz GLS cars in 2025, grouped into the DVSA's test areas.
Tyres and brakes together account for 63.6% of recorded failure items. These are recorded failures across the model, not faults every car has.
The 10 most common GLS MOT failures
Specific items recorded on Mercedes-Benz GLS cars that failed their 2025 MOT, as a share of all recorded failure items.
Together these 10 items make up 69.7% of everything testers recorded against failed Mercedes-Benz GLS cars. The rest is spread across many smaller items, and one failed test often records several at once.
What to look at on a GLS
The recorded failures above, grouped by area, biggest first.
1
Tyres
Recorded most often: tread depth below requirements of 1.6mm, condition has a cut in excess of the requirements deep enough to reach the ply or cords, condition has ply or cords exposed and condition has a bulge, caused by separation or partial failure of its structure. 48.9% of failure items.
2
Identification of the vehicle
Recorded most often: registration plates does not conform to the specified requirements. 4.5% of failure items.
3
Body, chassis, structure
Recorded most often: joints constant velocity boot split or insecure, no longer prevents the ingress of dirt. 4% of failure items.
4
Noise, emissions and leaks
Recorded most often: malfunction indicator lamp inoperative or indicates a malfunction. 3.9% of failure items.
The car's own MOT history matters more than any model average. A free MOT history check shows whether a specific GLS has failed on these items before, or had them noted as advisories. Buying one? See the used Mercedes-Benz GLS buying guide.
Already found one?
Check its finance, write-off, theft, mileage and keeper history with a £15 vehicle history report.
Mercedes-Benz GLS MOT FAQs
What is the Mercedes-Benz GLS MOT pass rate?
86.5% of Mercedes-Benz GLS cars passed their initial MOT first time in 2025, from 3,127 tests. That is 14.2 percentage points above the 72.3% average for all cars, and ranks 97th of 575 models.
What does a Mercedes-Benz GLS most commonly fail its MOT on?
The item testers recorded most often on Mercedes-Benz GLS cars failing their 2025 MOT was tread depth below requirements of 1.6mm, on 17% of failure items. Next were condition has a cut in excess of the requirements deep enough to reach the ply or cords (14.7%) and condition has ply or cords exposed (13.9%).
Which area causes the most Mercedes-Benz GLS MOT failures?
Across every recorded failure item, the largest area was tyres at 54.8%, followed by brakes at 8.8%.
Do older Mercedes-Benz GLS cars fail their MOT more often?
Mercedes-Benz GLS cars aged 3 to 5 years passed 85.7% of MOT tests in 2025, against 87.2% for cars aged 6 to 10 years.
Does this mean every Mercedes-Benz GLS has these problems?
No. These are the items testers recorded across every Mercedes-Benz GLS 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 GLS'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.