2018 · 6 years old at test · Diesel mostly

2018 Mercedes-Benz S-Class MOT pass rate and common faults

2,323 MOT tests in 2024. 90.2% passed first time, compared with 82.5% for all cars the same age.

109Well above average
Passed first time90.2%
Failed or needed repairs9.8%
Typical mileage at test62,000

Most common reasons for failing

Share of all 2,323 tests where this item caused a failure.

  1. Tread depth below requirements of 1.6mm2.0%
    94 marked dangerous
  2. Suspension arms - ball joint: ball joint excessively worn1.7%
  3. Malfunction indicator lamp: inoperative or indicates a malfunction1.1%
  4. Tyres - condition: has ply or cords exposed0.9%
    37 marked dangerous
  5. Tyres - condition: has a cut in excess of the requirements deep enough to reach the ply or cords0.8%
  6. Tyres - condition: has a bulge, caused by separation or partial failure of its structure0.6%
    18 marked dangerous
  7. Road Wheels - condition: fractured0.4%
    15 marked dangerous
  8. Brake pads: less than 1.5 mm thick0.4%
    13 marked dangerous
  9. Registration plates: does not conform to the specified requirements0.4%

Problem areas

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

  1. Tyres5.3%
  2. Suspension1.9%
  3. Emissions & leaks1.2%
  4. Lights & electrics1.2%
  5. Brakes1.0%
  6. Visibility (wipers, screen, mirrors)0.8%
  7. Number plates & VIN0.6%
  8. Wheels0.6%

Most common advisories

Not failures yet, but things the tester warned about.

  1. Tread depth below requirements of 1.6mm11.7%
  2. Brake pads: less than 1.5 mm thick4.3%
  3. Suspension arms - ball joint: ball joint excessively worn3.9%
  4. Brake discs: in such a condition that it is seriously weakened2.9%
  5. Brake discs: significantly and obviously worn2.7%

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: 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 2018 Mercedes-Benz S-Class?

In 2024, 90.2% of 2018 Mercedes-Benz S-Class cars passed their MOT first time, across 2,323 tests. The average for all 6-year-old cars was 82.5%.

What are the most common MOT failures on a 2018 Mercedes-Benz S-Class?

The most common failure reasons were tread depth below requirements of 1.6mm; suspension arms - ball joint: ball joint excessively worn; malfunction indicator lamp: inoperative or indicates a malfunction. The biggest problem area was tyres.

Is the 2018 Mercedes-Benz S-Class reliable at MOT time?

Its MOT Rank score is 109, which is well above average for a car of its age (100 means exactly average).