2020 · 4 years old at test · Diesel mostly

2020 Mercedes-Benz GLS MOT pass rate and common faults

412 MOT tests in 2024. 84.7% passed first time, compared with 86.9% for all cars the same age.

98Below average
Passed first time84.7%
Failed or needed repairs15.3%
Typical mileage at test38,000

Most common reasons for failing

Share of all 412 tests where this item caused a failure.

  1. Tread depth below requirements of 1.6mm4.1%
    34 marked dangerous
  2. Tyres - condition: has ply or cords exposed3.9%
    22 marked dangerous
  3. Tyres - condition: has a cut in excess of the requirements deep enough to reach the ply or cords2.4%
  4. Brake pads: worn down to wear indicator1.0%
  5. Individual direction indicators: with a multiple light source more than 1/2 not functioning1.0%
  6. Suspension arms - ball joint: ball joint excessively worn0.7%
  7. Tyres - condition: has a tear, caused by separation or partial failure of its structure0.5%
    3 marked dangerous
  8. Wipers: does not clear the windscreen effectively0.5%
  9. Brake pads: less than 1.5 mm thick0.5%
    2 marked dangerous
  10. Tyres - condition: has a bulge, caused by separation or partial failure of its structure0.5%
    2 marked dangerous

Problem areas

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

  1. Tyres12.9%
  2. Lights & electrics1.9%
  3. Brakes1.7%
  4. Suspension1.5%
  5. Seat belts & airbags1.0%
  6. Visibility (wipers, screen, mirrors)0.7%
  7. Number plates & VIN0.7%
  8. Emissions & leaks0.2%

Most common advisories

Not failures yet, but things the tester warned about.

  1. Tread depth below requirements of 1.6mm13.8%
  2. Brake pads: less than 1.5 mm thick7.3%
  3. Tyres - condition: has a cut in excess of the requirements deep enough to reach the ply or cords2.7%
  4. Brake discs: in such a condition that it is seriously weakened1.9%
  5. Tread depth: tread pattern not visible over the whole tread area when minimum depth required is 1.0mm1.9%

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: tread depth below requirements of 1.6mm. 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 2020 Mercedes-Benz GLS?

In 2024, 84.7% of 2020 Mercedes-Benz GLS cars passed their MOT first time, across 412 tests. The average for all 4-year-old cars was 86.9%.

What are the most common MOT failures on a 2020 Mercedes-Benz GLS?

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

Is the 2020 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).