Mercedes-BenzUsed-car reliability
At 7 years old, the average Mercedes-Benz fails its MOT less often than the average UK car.
MOT fail rate · 7-year-old cars
Fails less often than the average 7-year-old car (about 1 in 6 MOTs, 16.6%)
Where to start
The Mercedes-Benz models whose MOT tests at 7 years old most and least often ended in a fail.
Lowest fail rates
Mercedes-Benz SL7.4%fail rate
Mercedes-Benz S-Class9.5%fail rate
Mercedes-Benz GLS11.6%fail rateHighest fail rates
Mercedes-Benz X-Class18.4%fail rate
Mercedes-Benz CLA17.7%fail rate
Mercedes-Benz A-Class16.3%fail rateWhat actually goes wrong
The most common MOT faults across the Mercedes-Benz range, in plain English. Models with more MOT tests count for more. The percentage is the share of MOT tests on Mercedes-Benz cars that recorded that defect.
A tyre is worn, cut, damaged or otherwise not fit for the road. Tyres are the only thing connecting the car to the road, so this is always worth taking seriously.
MOT wording: Tyre worn close to the legal limit or worn on the edge
A rigid metal brake pipe is corroded, damaged, kinked, or leaking. These permanently fixed pipes carry pressurised brake fluid — any weakness is a serious safety concern.
MOT wording: Brake pipe corroded or covered in grease
A suspension arm, wishbone, strut, sub-frame, or anti-roll bar is worn, cracked, bent, or has excessive play. These structural parts hold the wheels in position and control body lean in corners.
MOT wording: Suspension part corroded, but not seriously weakened
The rubber boot (gaiter) over a driveshaft joint, called the CV joint, is split, perished or missing. The boot keeps grease in and dirt out, so a joint left without one wears out faster.
MOT wording: Drive shaft joint cover badly deteriorated
Across all Mercedes-Benz models; models with more MOT tests count for more.
The whole range
For each model, one number: the share of its MOT tests at 7 years old that ended in a fail. Retests count as tests. Lower is better. The UK average (about 1 in 6 MOTs, 16.6%) is shown for reference. Only models with enough MOT data at 7 years old are ranked. The rest sit just below, unranked.
The lowest 7-year fail rate of any Mercedes-Benz here.
Among the lower fail rates in the Mercedes-Benz range at 7 years old.
Among the lower fail rates in the Mercedes-Benz range at 7 years old.
Among the lower fail rates in the Mercedes-Benz range at 7 years old.
Among the lower fail rates in the Mercedes-Benz range at 7 years old.
Among the lower fail rates in the Mercedes-Benz range at 7 years old.
Among the lower fail rates in the Mercedes-Benz range at 7 years old.
Among the lower fail rates in the Mercedes-Benz range at 7 years old.
Above the Mercedes-Benz average, but below the UK average.
Above the Mercedes-Benz average, but below the UK average.
Above the Mercedes-Benz average, but below the UK average.
Above the Mercedes-Benz average, but below the UK average.
Above the Mercedes-Benz average, but below the UK average.
Above the Mercedes-Benz average, and at or above the UK average.
Above the Mercedes-Benz average, and at or above the UK average.
Fail rates are the share of MOT tests on 7-year-old cars ending in a fail, retests included (DVSA MOT results, 2025). UK average across all makes at the same age: 16.6%. How we count fail rates
Shown unranked. These models don’t have enough MOT data at 7 years old yet. They’re either too new (few cars old enough) or too old (few still on the road). Each is shown at the age with the most tests, so the percentages aren’t directly comparable to the list above.
Too new to rank
Too new to rank
Too new to rank
Too new to rank
Too old to rank
Too new to rank
Too old to rank
Too old to rank
Too old to rank
Too old to rank
Too old to rank
Too old to rank
Too old to rankAverages tell you the odds across the range. Enter a number plate to see that car’s own MOT history, its risk rating, and what’s likely to need attention.
