73 AUTO

MOT performance

Mercedes-Benz S-Class petrol: MOT pass rate and common failures

Of 14,498 MOT tests on petrol Mercedes-Benz S-Classs in 2023–2024 (on average 14.4 years old at test, median 72,387 miles), 81.4% passed first time, against 82.6% of 38,634 diesel Mercedes-Benz S-Class tests. Allowing for age, mileage and fuel, petrol Mercedes-Benz S-Classs failed 42% less often than comparable cars — 0.58× against 0.58× for the Mercedes-Benz S-Class as a whole.

14,498 MOT tests on 7,919 vehicles, 2023–2024 · Source: DVSA (Open Government Licence) · Analysis: 73 Auto

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At a glance

Mercedes-Benz S-Class petrol MOT results at a glance
FigureValueBasis
First-time pass rate81.4%±0.6 pts (95%), n = 14,498
All Mercedes-Benz S-Classs82.6%n = 55,571
Failures vs similar cars0.58×same age, mileage and fuel = 1.00; Mercedes-Benz S-Class overall 0.58×
Tests with a dangerous defect5.7%n = 14,498
Average age at test14.4 yearsn = 14,498
Registration years covered1972–2021DVSA first-use date

Petrol against the other Mercedes-Benz S-Class fuels

Official DVSA test results by fuel, with 73 Auto's adjusted ratio (failures against cars of the same age, mileage and fuel). The petrol cars were tested 4.9 years older on average than the diesel ones, so the raw pass rates partly reflect age; the adjusted column doesn't.

Mercedes-Benz S-Class MOT results by fuel
FuelTestsAverage ageFirst-time passvs similar carsDangerous
Diesel38,6349.5 yrs82.6%-42%6.5%
Petrol14,49814.4 yrs81.4%-42%5.7%
Hybrid2,3936 yrs89.0%-30%4.9%

Where petrol Mercedes-Benz S-Classs differ

  • Noise, emissions and leaks: petrol Mercedes-Benz S-Classs failed 49% less often than the Mercedes-Benz S-Class overall, relative to comparable cars (0.39× vs 0.76×).
  • Body, chassis and structure: petrol Mercedes-Benz S-Classs failed 32% more often than the Mercedes-Benz S-Class overall, relative to comparable cars (0.29× vs 0.22×).
  • Lights, reflectors and electrical: petrol Mercedes-Benz S-Classs failed 27% more often than the Mercedes-Benz S-Class overall, relative to comparable cars (0.43× vs 0.34×).
Mercedes-Benz S-Class petrol MOT failures by area, against the model overall
AreaPetrol (vs similar)All Mercedes-Benz S-Classs (vs similar)
Lights, reflectors and electrical6.0% (-57%)4.1% (-66%)
Suspension5.1% (-51%)4.7% (-50%)
Brakes4.7% (-45%)4.3% (-43%)
Tyres4.5% (-21%)5.3% (-18%)
Driver's view of the road2.8% (-51%)2.2% (-54%)
Noise, emissions and leaks2.1% (-61%)2.7% (-24%)
Body, chassis and structure1.5% (-71%)0.9% (-78%)
Seat belts and airbags1.4% (-14%)1.0% (-26%)

Most common petrol Mercedes-Benz S-Class failure items

2 of these 5 items are not among the Mercedes-Benz S-Class's ten most common failures overall.

Most common petrol Mercedes-Benz S-Class MOT failure items
ItemAreaShare of tests
Ball joint: ball joint excessively wornSuspension2.17%
Tread depth: tread depth below requirements of 1.6mmTyres1.56%
Position lamp: not workingLights, reflectors and electrical1.20%
Malfunction indicator lamp: inoperative or indicates a malfunctionNoise, emissions and leaks0.99%
Condition: has ply or cords exposedTyres0.98%

Pass rate by age, by fuel

Mercedes-Benz S-Class MOT pass rate by age and fuel
Age at test (years)petrol pass rate (tests)diesel pass rate (tests)
3-492.0% (1,092)91.9% (4,966)
5-689.3% (1,976)88.9% (7,550)
7-888.9% (1,754)86.2% (6,826)
9-1088.9% (808)81.8% (4,444)
11-1281.8% (515)78.0% (3,881)
13-1579.8% (908)74.4% (4,894)
16+75.2% (7,363)71.8% (5,541)

Mercedes-Benz S-Class by registration year

What this does and doesn't tell you

Fuel is DVSA's recorded fuel type; plug-in and self-charging hybrids are grouped as hybrid. A difference between fuels can come from the engines themselves, or from how the cars are used — diesels typically cover more miles, and the adjusted ratio allows for mileage band but not for every difference in use. For one car, its own MOT history is the better guide: see MOT check.

Check a specific petrol Mercedes-Benz S-Class

Enter a UK registration to see that car's own MOT history and what it is likely to cost to own. Your first check is free and shows the vehicle summary and its headline ownership cost. The category-by-category breakdown is part of a paid check.

UK number plate or 17-character VIN

About this data. These are MOT test results, not a measure of mechanical reliability: a car's MOT outcome reflects its condition on the day, which depends on how it has been maintained and driven as well as how it was built. Figures cover class 4 vehicles (cars and light vans), normal tests only (retests excluded), outcomes pass, fail and pass after rectification at the station; vehicles at least 2.5 years old at test. Tests from 2023-01-01 to 2024-12-30. “Compared with similar cars” means compared with the national rate for cars of the same age, mileage band and fuel. Contains public sector information licensed under the Open Government Licence v3.0. Makes and models are matched to 73 Auto's vehicle catalogue; tests that can't be matched are left out rather than guessed. See how the MOT figures are produced.