86.5%
Mercedes-Benz GLS pass rate
Used Mercedes-Benz GLS buying guide
In 2025, Mercedes-Benz GLS cars passed 86.5% of 3,127 initial MOT tests, 14.2 points above the 72.3% UK average. Here is where it fails and what to check before you buy.
Looking at a specific GLS? Check its finance, write-off, stolen, mileage and keeper history. £15, no account needed.
Mercedes-Benz GLS MOT record in brief
Initial MOT tests in 2025, retests excluded.
72.3%
UK average, all cars
+14.2
percentage points above average
Ranked on pass rate the GLS sits 97th of 575 models in the data. Mercedes-Benz as a brand averaged 77.1%, so this model runs 9.4 points ahead of its own brand. Mercedes-Benz GLS cars aged 3 to 5 years passed 85.7% of MOT tests in 2025; examples aged 6 to 10 years did better, at 87.2%.
A pass rate is not a reliability score. The full Mercedes-Benz GLS MOT record has the pass rate by age, every common failure and how the GLS compares with similar cars.
GLS fuel types
Diesel made up 88.1% of Mercedes-Benz GLS MOT tests in 2025, against 39.3% across all models in this data. Almost every used example you look at will be a diesel.
Where the GLS fails its MOT
Where Mercedes-Benz GLS cars that failed their 2025 MOT were marked down, as a share of all recorded failure items.
The specific items testers recorded most often were tread depth below requirements of 1.6mm (17%), 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%). See every common GLS MOT failure.
These are DVSA failure records across every Mercedes-Benz GLS that failed, not a claim that every GLS has these problems.
What should you check when buying a used GLS?
The areas above, most common first, and what an MOT tester looks at in each.
1
Tyres
Check tread depth across the full width of every tyre (the legal minimum is 1.6mm), and look for cuts, bulges and uneven wear. 54.8% of GLS failure items.
2
Brakes
Make sure the pedal feels firm, the car stops in a straight line, the handbrake holds on a slope and no brake warning light is showing. 8.8% of GLS failure items.
3
Lamps, reflectors and electrical equipment
Walk round with every light on: headlights, brake lights, indicators, fog lights and the number plate lamp. Check no warning lights stay on after starting. 8.4% of GLS failure items.
4
Identification of the vehicle
Match the number plates and VIN to the V5C logbook, and check the plates are legal. 5.5% of GLS failure items.
5
Body, chassis, structure
Look underneath and along the sills for corrosion, and check for damaged or poorly repaired panels. 5.1% of GLS failure items.
None of this replaces the car's own record. Run a free MOT history check on the registration to see every test, advisory and recorded mileage for that car.
What the MOT record doesn't tell you
Knowing Mercedes-Benz GLS failures cluster around tyres and brakes tells you what to inspect. It tells you nothing about whether the car is safe to buy. An MOT does not show money still owed on the car, a write-off, a theft record or a clocked odometer.
Check the exact GLS you are looking at. One £15 report, instant results, backed by a £30,000 data guarantee. More on the Mercedes-Benz history check.
- Outstanding finance
- Write-off records
- Stolen markers
- Mileage history
- Previous keepers
Other used Mercedes-Benz models
The most-tested Mercedes-Benz models in 2025, with how their MOT pass rate compares with the GLS.
- Used Mercedes-Benz A-Class 78.4% MOT pass rate
- Used Mercedes-Benz C-Class 74.7% MOT pass rate
- Used Mercedes-Benz E-Class 77.4% MOT pass rate
- Used Mercedes-Benz GLA 83.3% MOT pass rate
- Used Mercedes-Benz Vito 67.3% MOT pass rate
- Used Mercedes-Benz GLC 86.4% MOT pass rate
See all 35 Mercedes-Benz models ranked by MOT pass rate.
Used Mercedes-Benz GLS FAQs
Is the Mercedes-Benz GLS reliable?
MOT data does not measure reliability. It records whether a car met the roadworthiness standard on the day of its test. What it does show is an 86.5% first-time pass rate for the Mercedes-Benz GLS across 3,127 tests in 2025, above the 72.3% average for all cars.
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; examples aged 6 to 10 years did better, at 87.2%. On an older example, the car's own MOT history tells you more than the model average.
What should I check before buying a used Mercedes-Benz GLS?
On the car itself, start with the areas it most often fails on: tyres, brakes and lamps, reflectors and electrical equipment. Then check the individual car's history: outstanding finance, insurance write-off records, stolen markers, mileage and previous keepers. None of these appear in the MOT record or on the V5C.
How do I check a Mercedes-Benz GLS's history?
Enter the registration of the specific car. A Carpeep car history check reports outstanding finance, write-off category, stolen markers, mileage history, previous keepers, MOT and tax status, import and export markers and scrapped status in one £15 report.
MOT figures are aggregated from the DVSA MOT Anonymised data set for 2025 (class 4 initial tests, retests excluded), licensed under the Open Government Licence v3.0. MOT results describe roadworthiness at test, not mechanical reliability.