90%
Mercedes-Benz GLB
Mercedes-Benz GLB MOT pass rate and common problems
The Mercedes-Benz GLB passed 90% of its initial MOT tests in 2025, 17.7 percentage points above the 72.3% UK average. The item testers recorded most often was condition has a cut in excess of the requirements deep enough to reach the ply or cords.
Checking a specific car? Its own results, advisories and recorded mileages are in a free MOT history check.
How the GLB 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 GLB runs 12.9 points ahead of the Mercedes-Benz average. It is 2nd of the 35 Mercedes-Benz models in the data. The average GLB arrived at its test 3.7 years old with 34,539 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.
GLB MOT pass rate by age
The same 2025 tests split by the car's age at test.
| Age at test | Tests | Pass rate | vs UK average |
|---|---|---|---|
| 3 to 5 years | 8,186 | 88.9% | 16.6 pts above |
Every Mercedes-Benz GLB tested in 2025 was aged 3 to 5 years, so there is no other age group to compare with. The UK average of 72.3% covers cars of every age, so compare like with like.
Where GLB failures cluster
Every failure item recorded on Mercedes-Benz GLB cars in 2025, grouped into the DVSA's test areas.
Tyres and brakes together account for 59.7% of recorded failure items. These are recorded failures across the model, not faults every car has.
The 10 most common GLB MOT failures
Specific items recorded on Mercedes-Benz GLB cars that failed their 2025 MOT, as a share of all recorded failure items.
Together these 10 items make up 71.4% of everything testers recorded against failed Mercedes-Benz GLB cars. The rest is spread across many smaller items, and one failed test often records several at once.
What to look at on a GLB
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 and tread depth below requirements of 1.6mm. 36.5% of failure items.
2
Brakes
Recorded most often: brake pads less than 1.5 mm thick and brake pads worn down to wear indicator. 13% of failure items.
3
Lamps, reflectors and electrical equipment
Recorded most often: headlamp aim too high, headlamp aim too low and horn not working. 11.9% of failure items.
4
Visibility
Recorded most often: wipers does not clear the windscreen effectively. 6.3% of failure items.
The car's own MOT history matters more than any model average. A free MOT history check shows whether a specific GLB has failed on these items before, or had them noted as advisories. Buying one? See the used Mercedes-Benz GLB buying guide.
Already found one?
Check its finance, write-off, theft, mileage and keeper history with a £15 vehicle history report.
Mercedes-Benz GLB MOT FAQs
What is the Mercedes-Benz GLB MOT pass rate?
90% of Mercedes-Benz GLB cars passed their initial MOT first time in 2025, from 12,352 tests. That is 17.7 percentage points above the 72.3% average for all cars, and ranks 41st of 575 models.
What does a Mercedes-Benz GLB most commonly fail its MOT on?
The item testers recorded most often on Mercedes-Benz GLB cars failing their 2025 MOT was condition has a cut in excess of the requirements deep enough to reach the ply or cords, on 20.3% of failure items. Next were brake pads less than 1.5 mm thick (9.3%) and condition has ply or cords exposed (8.2%).
Which area causes the most Mercedes-Benz GLB MOT failures?
Across every recorded failure item, the largest area was tyres at 42.1%, followed by brakes at 17.6%.
Does this mean every Mercedes-Benz GLB has these problems?
No. These are the items testers recorded across every Mercedes-Benz GLB 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 GLB'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.