Across 2,784 MOT tests of the Mercedes-Benz GLB in the DfT's 2023 MOT data (initial tests, retests excluded), 10.1% failed — about 1 in 10. The parts that fail most are tyres (5.9% of tests).
Allowing for age and mileage, the Mercedes-Benz GLB has 19% fewer MOT failures than the average car of the same age and mileage.
This is a small sample of tests, so treat the percentages as rough.
The MOT checks safety and emissions items — brakes, suspension, steering, lights, tyres, body structure and exhaust emissions. It does not test engines, gearboxes or most electronics, so those faults only show up here when they cause an emissions failure or a leak.
GLB (2019–2025)
MOT: 10.1% of 2,784 initial tests failed — 19% fewer failures than the average car of the same age and mileage
| # | Part / area | Share of MOT tests failing |
|---|---|---|
| 1 | tyres | 5.9% |
Questions
What fails most on a Mercedes-Benz GLB at MOT?
The most common MOT failure is tyres: 5.9% of Mercedes-Benz GLB MOT tests in the 2023 data failed on tyres.
How often does a Mercedes-Benz GLB fail its MOT?
10.1% of Mercedes-Benz GLB MOT tests in the 2023 data failed (about 1 in 10), counting initial tests only, across 2,784 tests. Allowing for age and mileage, that is 19% fewer MOT failures than the average car of the same age and mileage.
Is the Mercedes-Benz GLB reliable?
On MOT results, the Mercedes-Benz GLB has 19% fewer MOT failures than the average car of the same age and mileage. MOT data covers safety and emissions items, not engines or gearboxes.
Does this Mercedes-Benz GLB data cover engine and gearbox problems?
No. The MOT checks safety and emissions items — brakes, suspension, steering, lights, tyres, body structure and exhaust emissions. It does not test engines, gearboxes or most electronics, so those faults only show up here when they cause an emissions failure or a leak.