2,826 tests in 2025
Mercedes-Benz Gls reliability and MOT pass rate
87.8% passed first time. The 12.2% fail rate is 10.4 points better than the all-car average, on a median example 7 years old with 55,338 miles.
MOT pass rates / Mercedes-Benz
Pass rate
87.8%
22.6% of all cars failed; 12.2% of these did.
Fixed on the day
1.3%
Passed after a defect was put right during the visit.
Median at test
55,338 mi
7 years old.
Fail rate by age
| Age at test | Tests | Fail rate |
|---|---|---|
| 3-5 years | 991 | 12.7% |
| 6-9 years | 1,793 | 12% |
| 10-13 years | 1 | — |
| 14+ years | 0 | — |
What the Gls fails on
Share of failed tests with at least one fail item in each DVSA inspection section. A test can fail in several sections at once.
- Tyres241 dangerous64.5%
- Brakes20 dangerous10.5%
- Body, chassis, structure8.7%
- Lamps, reflectors and electrical equipment7.3%
- Noise, emissions and leaks6.4%
- Suspension4 dangerous6.4%
- Seat belts and supplementary restraint systems4.4%
- Road Wheels13 dangerous3.8%
Is the Gls getting worse?
The fail rate rose 1.5 points to 12% from 2022 to 2025 while the median one tested aged 3 years. Ageing alone would predict about 6.6 points, so it is holding up better than the fleet average for its age.
| Year | Tests | Median age | Fail rate | All cars | |
|---|---|---|---|---|---|
| 2022 | 2,138 | 5 | 10.5% | 22.5% | |
| 2023 | 2,053 | 6 | 10.1% | 22.8% | |
| 2024 | 1,657 | 7 | 10.7% | 23.2% | |
| 2025 | 1,738 | 8 | 12% | 22.6% |
Fail rate is first attempts at class 4 tests. Median age is the age of a typical Gls at its test that year, and it is the number to watch: across the whole fleet each extra year of age adds roughly 1.9 points to the fail rate, so a model whose age and fail rate rise together is simply getting older.
The exact defects that fail it
Every failure item DVSA recorded against a Gls in 2025, counted by how many tests each one appeared on.
- 1Condition: has a cut in excess of the requirements deep enough to reach the ply or cords72 tests
- 2Condition: has ply or cords exposed72 tests
- 3Tread depth: tread depth below requirements of 1.6mm68 tests
- 4Joints: constant velocity boot split or insecure, no longer prevents the ingress of dirt23 tests
- 5Malfunction indicator lamp: inoperative or indicates a malfunction21 tests
- 6Condition: has a bulge, caused by separation or partial failure of its structure21 tests
- 7Brake pads: less than 1.5 mm thick17 tests
- 8Ball joint: ball joint excessively worn11 tests
What wears out first
Advisories are the tester flagging wear that is still legal. A typical Gls collects 2.16 of them per test, and these are the ones that come up most. Treat it as the running-repairs list for the next year or two.
- 1Tread depth: tread depth below requirements of 1.6mm450 tests
- 2Brake pads: less than 1.5 mm thick192 tests
- 3Brake discs: in such a condition that it is seriously weakened103 tests
- 4Tread depth: tread pattern not visible over the whole tread area when minimum depth required is 1.0mm87 tests
- 5Brake discs: significantly and obviously worn85 tests
- 6Non-component advisories: Nail in tyre80 tests
- 7Condition: has a cut in excess of the requirements deep enough to reach the ply or cords71 tests
- 8Non-component advisories: Child Seat fitted not allowing full inspection of adult belt63 tests
Questions
What is the Mercedes-Benz Gls MOT pass rate?
87.8% of the 2,826 Mercedes-Benz Gls first-attempt MOTs in 2025 passed. The fail rate of 12.2% compares with 22.6% across all cars. A further 1.3% passed after a defect was fixed during the test visit.
What does a Mercedes-Benz Gls usually fail on?
The single most common failure is "Condition: has a cut in excess of the requirements deep enough to reach the ply or cords", recorded on 72 failed tests, followed by "Condition: has ply or cords exposed" and "Tread depth: tread depth below requirements of 1.6mm". By section, tyres appears in 64.5% of failures, brakes appears in 10.5% of failures, body, chassis, structure appears in 8.7% of failures.
Does age change the odds?
Sharply. At 3 to 5 years old the fail rate was 12.7%; at 6-9 years it was 12%. The median Mercedes-Benz Gls tested in 2025 was 7 years old with 55,338 miles.
Is the Mercedes-Benz Gls getting less reliable?
The fail rate rose 1.5 points to 12% from 2022 to 2025 while the median one tested aged 3 years. Ageing alone would predict about 6.6 points, so it is holding up better than the fleet average for its age.
First-attempt class 4 tests, 2025, from DVSA’s anonymised MOT data (OGL v3, retrieved 2026-09-12). DVSA records newer cars trim by trim; this page adds every Gls trim together. Year-on-year figures come from the same DVSA extracts for 2026 and earlier years. Full method on the pass rates hub.
DVSA has published 19 safety recalls naming the Mercedes-Benz Gls: Mercedes-Benz Gls recalls.
Other Mercedes-Benz models
Checking a particular Gls?
The odds above are the model. The car in front of you has its own record: every test, every advisory, the mileage at each one.
Due a test? Find an approved MOT station near you.