2021 · 3 years old at test · Diesel mostly

2021 Mercedes-Benz GLS MOT pass rate and common faults

304 MOT tests in 2024. 85.5% passed first time, compared with 87.6% for all cars the same age.

98Below average
Passed first time85.5%
Failed or needed repairs14.5%
Typical mileage at test29,000

Most common reasons for failing

Share of all 304 tests where this item caused a failure.

  1. Tyres - condition: has a cut in excess of the requirements deep enough to reach the ply or cords3.6%
  2. Tyres - condition: has ply or cords exposed3.3%
    16 marked dangerous
  3. Tread depth below requirements of 1.6mm2.6%
    27 marked dangerous
  4. Tyres - condition: has a bulge, caused by separation or partial failure of its structure1.6%
    7 marked dangerous
  5. Brake pads: less than 1.5 mm thick1.3%
    6 marked dangerous
  6. Brake pads: worn down to wear indicator1.0%
  7. Headlamp aim: too high1.0%
  8. Other suspension component - ball joint: ball joint excessively worn0.7%
  9. Registration plates: does not conform to the specified requirements0.7%
  10. Road Wheels - condition: fractured0.3%
    1 marked dangerous

Problem areas

Failure items found per 100 tests, by part of the car.

  1. Tyres12.2%
  2. Brakes2.6%
  3. Lights & electrics1.3%
  4. Suspension0.7%
  5. Number plates & VIN0.7%
  6. Seat belts & airbags0.7%
  7. Visibility (wipers, screen, mirrors)0.7%
  8. Wheels0.3%

Most common advisories

Not failures yet, but things the tester warned about.

  1. Tread depth below requirements of 1.6mm13.2%
  2. Brake pads: less than 1.5 mm thick8.2%
  3. Non-component advisories: Child Seat fitted not allowing full inspection of adult belt4.6%
  4. Tread depth: tread pattern not visible over the whole tread area when minimum depth required is 1.0mm3.6%
  5. Tyres - condition: has a cut in excess of the requirements deep enough to reach the ply or cords3.0%

What this means if you are buying one

This model year fails more often than most cars its age, so budget for repairs and check the history carefully. Before buying, check the area that fails most: tyres - condition: has a cut in excess of the requirements deep enough to reach the ply or cords. Then look up the car's own MOT history on GOV.UK with its number plate, and look for repeat advisories.

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Questions

What is the MOT pass rate for a 2021 Mercedes-Benz GLS?

In 2024, 85.5% of 2021 Mercedes-Benz GLS cars passed their MOT first time, across 304 tests. The average for all 3-year-old cars was 87.6%.

What are the most common MOT failures on a 2021 Mercedes-Benz GLS?

The most common failure reasons were tyres - condition: has a cut in excess of the requirements deep enough to reach the ply or cords; tyres - condition: has ply or cords exposed; tread depth below requirements of 1.6mm. The biggest problem area was tyres.

Is the 2021 Mercedes-Benz GLS reliable at MOT time?

Its MOT Rank score is 98, which is below average for a car of its age (100 means exactly average).