Mercedes-Benz GLB reliability, MPG and running costs
Figures updated
The Mercedes-Benz GLB is a car. In 2024 MOT tests it scored 132 for reliability (100 is average), ranking 106 of 442, and 10.0% failed first time against a UK average of 28.5%. Its most common MOT failure is condition (2.6% of tests).
Ranked 106 of 442 cars in the 2024 MOT Reliability League
In 2024, 5,450 Mercedes-Benz GLBs aged 3 to 20 had an MOT and 10.0% failed first time (UK average 28.5%). Taking age and mileage into account, the Mercedes-Benz GLB is 24% less likely to fail than the average car of the same age and mileage. At the first MOT, at three years old, 9.2% failed (UK 12.7%).
First-time fail rate
10.0%
UK 28.5%
Fail rate at 3 years
9.2%
UK 12.7%
Average miles a year
9,700
Typical age at test: 3 years
Mercedes-Benz GLB MOT failure rate by age
Most common Mercedes-Benz GLB MOT faults
- Condition: has a cut in excess of the requirements deep enough to reach the ply or cords2.6% of tests
- Condition: has ply or cords exposed1.1% of tests
- Tread depth: tread depth below requirements of 1.6mm0.9% of tests
- Brake pads: less than 1.5 mm thick0.9% of tests
- Wipers: does not clear the windscreen effectively0.7% of tests
- Headlamp aim: too high0.6% of tests
What the Mercedes-Benz GLB fails on
| Area | Tests failing | vs similar cars |
|---|---|---|
| Tyres | 4.9% | About average |
| Lights and electrics | 1.5% | ▼ 48% less often |
| Brakes | 1.5% | ▼ 30% less often |
| Visibility | 1.3% | ▼ 60% less often |
| Seat belts and airbags | 0.6% | ▲ 1.9× as often |
| Suspension | 0.6% | ▼ 22% less often |
| Exhaust and emissions | 0.3% | ▼ 51% less often |
| Wheels | 0.2% | ▲ 1.4× as often |
| Body and structure | 0.2% | ▼ 29% less often |
| Steering | 0.0% | ▼ 70% less often |
What MPG does the Mercedes-Benz GLB do?
Official economy for the Mercedes-Benz GLB ranges from 31.7 to 52.3mpg across the 16 versions listed by the Vehicle Certification Agency (2021–2025). A typical petrol version manages 37.2mpg and a typical diesel 49.6mpg. Expect 10–15% less in real-world driving.
Work out a journey's fuel costHow much is road tax on a Mercedes-Benz GLB?
Any Mercedes-Benz GLB first registered from April 2017 pays the standard rate of £200 a year after its first year (2026/27 rates).
Work out tax for a specific carMercedes-Benz GLB specs and running costs
Official figures for 16 versions sold in the UK between 2021 and 2025.
Fuel types
Diesel, Petrol
Official economy
31.7–52.3 mpg
CO2
143–203 g/km
Power
150–306 PS
| Version | Fuel | Economy | CO2 | Car tax | Company car tax |
|---|---|---|---|---|---|
| GLB GLB 200 d150 PS · A8 · listed 2025 | Diesel | 51.4 mpg | 145g | £200 | 37% |
| GLB GLB 220 d 4MATIC190 PS · A8 · listed 2025 | Diesel | 48.7 mpg | 152g | £200 | 37% |
| GLB GLB 200163 PS · A7 · listed 2025 | Petrol | 42.2 mpg | 151g | £200 | 36% |
| GLB AMG GLB 35 4MATIC306 PS · A8 · listed 2025 | Petrol | 31.7 mpg | 203g | £200 | 37% |
| GLB Mercedes-AMG GLB 35 4MATIC225 PS · A8 · listed 2024 | Petrol | 31.7 mpg | 203g | £200 | 37% |
| GLB .5 GLB 200 d150 PS · A8 · listed 2021 | Diesel | 52.3 mpg | 143g | £200 | – |
| GLB GLB 200 d 4MATIC150 PS · A8 · listed 2021 | Diesel | 43.5 mpg | 149g | £200 | – |
| GLB SUV .5 GLB 200 d150 PS · A8 · listed 2021 | Diesel | 50.4 mpg | 143g | £200 | – |
| GLB SUV .5 GLB 200 d 4MATIC150 PS · A8 · listed 2021 | Diesel | 49.6 mpg | 149g | £200 | – |
| GLB .5 GLB 220 d 4MATIC190 PS · A8 · listed 2021 | Diesel | 49.6 mpg | 149g | £200 | – |
| GLB SUV .5 GLB 220 d 4MATIC190 PS · A8 · listed 2021 | Diesel | 48.7 mpg | 150g | £200 | – |
| GLB .5 GLB 200163 PS · A7 · listed 2021 | Petrol | 40.9 mpg | 156g | £200 | – |
| GLB SUV .5 GLB 200163 PS · A7 · listed 2021 | Petrol | 40.4 mpg | 157g | £200 | – |
| GLB SUV .5 GLB 250224 PS · A8 · listed 2021 | Petrol | 37.2 mpg | 175g | £200 | – |
| GLB SUV .5 GLB 250 4MATIC224 PS · A8 · listed 2021 | Petrol | 36.7 mpg | 178g | £200 | – |
Economy and CO2 are official WLTP figures. Car tax is the yearly rate at current rates for a car first registered in the year listed, before any expensive car supplement. Company car tax is the 2026/27 benefit-in-kind rate. Showing the 15 most recent of 16 versions.
What a Mercedes-Benz GLB costs to fuel
- petrol, typical official 37.2mpg…
- diesel, typical official 49.6mpg…
Official figures are usually 10–15% better than real-world driving.
Work out a journey in a Mercedes-Benz GLBBuying a used Mercedes-Benz GLB?
Check the MOT history of the exact car: every result, advisory and mileage reading, free.
Other Mercedes-Benz models
Frequently asked questions
›Is the Mercedes-Benz GLB reliable?
Its MOT record is better than average: the Mercedes-Benz GLB is 24% less likely to fail than the average car of the same age and mileage, with a reliability score of 132 in our 2024 league (100 is average).
›What are common problems with the Mercedes-Benz GLB?
The most common MOT fault is “Condition: has a cut in excess of the requirements deep enough to reach the ply or cords”, found in 2.6% of tests.
›What MPG does the Mercedes-Benz GLB do?
Official economy for the Mercedes-Benz GLB ranges from 31.7 to 52.3mpg across the 16 versions listed by the Vehicle Certification Agency (2021–2025). A typical petrol version manages 37.2mpg and a typical diesel 49.6mpg. Expect 10–15% less in real-world driving.
›How much is road tax on a Mercedes-Benz GLB?
Any Mercedes-Benz GLB first registered from April 2017 pays the standard rate of £200 a year after its first year (2026/27 rates).
›How many Mercedes-Benz GLBs fail their MOT?
10.0% of Mercedes-Benz GLBs aged 3 to 20 failed their MOT first time in 2024, and 9.2% failed at their first MOT.
Sources: DVSA anonymised MOT tests 2024, all versions of the Mercedes-Benz GLB combined (Open Government Licence v3.0); official economy and CO2 from Vehicle Certification Agency data, © Crown copyright. VCA cannot accept liability for its accuracy. How we calculate the league.