Used car guide

2020 Mercedes-Benz S-Class: common problems and MOT failures

What MOT testers find on the Mercedes-Benz S-Class first registered in 2020: we looked at the 775 MOTs these cars had during 2023–2025. Plus known faults and what to look at before you buy one.

775MOTs of 2020 cars, done in 2023–2025
93%pass first time (all 2020 cars: 87%)
8,800typical miles a year
21%had tyres flagged

Common 2020 Mercedes-Benz S-Class MOT failures and advisories

The share of 2020 Mercedes-Benz S-Class MOT tests where testers flagged each area, as a fail or an advisory. Rough prices are typical independent-garage costs.

  • Tyres
    21% of testsRough price £70–£150

    At the viewing: Check the tread on all four tyres, including the inside edges, and look for cracks or bulges.

  • Brakes
    7% of testsRough price £150–£350

    At the viewing: Look for a lip on the disc edges and feel for judder or pulling when braking firmly from about 40mph.

  • Lights and electrics
    3% of testsRough price £10–£80

    At the viewing: Ask a friend to check every light, including brake lights and indicators, while you operate them.

  • Wipers, windscreen and mirrors
    3% of testsRough price £15–£250

    At the viewing: Check for chips in the driver's view, and test the wipers and washers.

  • Seats and seatbelts
    1% of testsRough price £80–£250

    At the viewing: Pull each seatbelt sharply. It should lock, and retract cleanly.

  • Oil and fluid leaks
    1% of testsRough price £80–£600

    At the viewing: Look under the engine and on the ground where the car is usually parked for fresh oil or fluid.

Questions to ask the seller before buying a 2020 Mercedes-Benz S-Class

Ask before you travel to see it. A seller who knows the car will have answers, and receipts.

  1. Can I see the service history and receipts for any big jobs?

Looking at a Mercedes-Benz S-Class?

Check the actual car: its own MOT history, mileage and what to ask the seller. Free, no sign-up.

Other years

Every year of the Mercedes-Benz S-Class compared

YearMOT testsMost flagged
2026–Too new for MOT data
2025–Too new for MOT data
2024–Too new for MOT data
2023513Tyres 14%
2022651Tyres 12%
2021181Tyres 18%
20196,969Tyres 19%
20186,956Tyres 18%
20177,118Tyres 22%
20168,055Tyres 23%
20156,498Tyres 23%
20144,858Tyres 22%
20132,948Brakes 26%
20123,634Brakes 31%
20112,761Brakes 30%
20102,549Brakes 31%
20092,529Brakes 37%
20082,858Brakes 39%
20073,814Brakes 40%
20063,082Brakes 37%
20051,569Brakes 37%
20041,856Brakes 37%
20031,931Brakes 35%
20021,143Brakes 33%
20011,009Brakes 34%
2000768Suspension 35%
1999491Brakes 34%
1998501Brakes 32%
1997354Brakes 34%
1996319Brakes 29%
1995258Suspension 40%
1994149Suspension 32%
1993–Too few tests
1991133Brakes 18%
1990128Suspension 27%

Where this comes from: the DVSA's anonymised results for every MOT test done in Great Britain during 2023–2025, counting the MOTs of Mercedes-Benz S-Class cars first registered in 2020. "Flagged" includes advisories, so it isn't the same as a fail rate. How we score