2020 · 4 years old at test · Diesel mostly

2020 Mercedes-Benz S-Class MOT pass rate and common faults

644 MOT tests in 2024. 91.1% passed first time, compared with 86.9% for all cars the same age.

105Above average
Passed first time91.1%
Failed or needed repairs8.9%
Typical mileage at test45,000

Most common reasons for failing

Share of all 644 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 cords1.7%
  2. Tread depth below requirements of 1.6mm1.4%
    20 marked dangerous
  3. Tyres - condition: has ply or cords exposed1.1%
    11 marked dangerous
  4. Brake pads: less than 1.5 mm thick1.1%
    10 marked dangerous
  5. Tyres - condition: has a lump, caused by separation or partial failure of its structure0.5%
    4 marked dangerous
  6. Tyres - condition: has a bulge, caused by separation or partial failure of its structure0.5%
    4 marked dangerous
  7. Suspension arms - ball joint: ball joint excessively worn0.5%
  8. Seat belts - condition: buckle not functioning as intended0.3%
  9. Washers: not working0.3%
  10. Washers: provides insufficient washer liquid0.3%

Problem areas

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

  1. Tyres5.9%
  2. Brakes1.4%
  3. Visibility (wipers, screen, mirrors)1.1%
  4. Lights & electrics0.9%
  5. Suspension0.6%
  6. Seat belts & airbags0.5%
  7. Wheels0.5%
  8. Emissions & leaks0.5%

Most common advisories

Not failures yet, but things the tester warned about.

  1. Tread depth below requirements of 1.6mm14.3%
  2. Brake pads: less than 1.5 mm thick5.6%
  3. Brake discs: in such a condition that it is seriously weakened3.1%
  4. Tyres - condition: has a cut in excess of the requirements deep enough to reach the ply or cords3.0%
  5. Tread depth: tread pattern not visible over the whole tread area when minimum depth required is 1.0mm2.2%

What this means if you are buying one

This model year does better than most cars its age, so it is a reasonable used buy on MOT record alone. 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 2020 Mercedes-Benz S-Class?

In 2024, 91.1% of 2020 Mercedes-Benz S-Class cars passed their MOT first time, across 644 tests. The average for all 4-year-old cars was 86.9%.

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

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

Is the 2020 Mercedes-Benz S-Class reliable at MOT time?

Its MOT Rank score is 105, which is above average for a car of its age (100 means exactly average).