Mercedes-Benz CLA MOT failure rate and common faults
73,975 Mercedes-Benz CLA cars aged 3 to 20 took their MOT in 2025, and 19.4% failed at the first attempt. An average car of the same age failed 19.2% of the time, which makes the Mercedes-Benz CLA about as likely to fail than the typical car on the road. Here is what fails, and which years to look for.
19.4%
failed first time
73,975 MOT tests in 2025
+1%
vs same age average
average car of this age mix: 19.2%
131 of 208
age adjusted rank
among cars; 1 fails least
108.7
dangerous defects per 1,000
same age average: 78.1
What fails on a Mercedes-Benz CLA MOT
Failure items recorded per 1,000 tests, by part of the car, set against an average car with exactly the same spread of ages. A figure well above average is a weak spot worth checking before you buy.
The most common Mercedes-Benz CLA MOT failures
The individual failure items testers recorded most often, per 1,000 tests.
| Failure item | Area | Per 1,000 tests |
|---|---|---|
| Tread depth below requirements of 1.6mm | Tyres | 30.6 |
| Tyres: has a cut in excess of the requirements deep enough to reach the ply or cords | Tyres | 27.5 |
| Tyres: has ply or cords exposed | Tyres | 26.3 |
| Coil spring: fractured or broken | Suspension | 22.4 |
| Brake pads: less than 1.5 mm thick | Brakes | 19.1 |
| Malfunction indicator lamp: inoperative or indicates a malfunction | Engine, emissions and leaks | 17.2 |
| Linkage ball joint dust cover: ball joint dust cover no longer prevents the ingress of dirt | Suspension | 14.1 |
| Washers: provides insufficient washer liquid | Windscreen, wipers and mirrors | 13.1 |
| Wipers: does not clear the windscreen effectively | Windscreen, wipers and mirrors | 11.6 |
| Headlamp aim: too low | Lights and electrics | 9.4 |
Mercedes-Benz CLA MOT failure rate by year
Every car fails more often as it ages, so each registration year is compared with the average for all cars of the same age. Years with fewer than 500 tests are left out.
| First registered | Tests | Failed | Same age average | Average mileage |
|---|---|---|---|---|
| 2022 | 11,366 | 12.7% | 11.4% | 31,000 |
| 2021 | 9,549 | 13.9% | 12.8% | 39,700 |
| 2020 | 7,494 | 15.5% | 14.1% | 45,100 |
| 2019 | 8,237 | 16.6% | 16.5% | 50,000 |
| 2018 | 8,392 | 20.0% | 19.1% | 60,300 |
| 2017 | 8,247 | 23.2% | 21.8% | 72,500 |
| 2016 | 7,595 | 24.4% | 25.1% | 81,900 |
| 2015 | 6,743 | 26.4% | 28.1% | 89,300 |
| 2014 | 4,274 | 28.1% | 31.4% | 94,800 |
| 2013 | 2,078 | 30.2% | 34.3% | 99,200 |
Advisories to look for in a Mercedes-Benz CLA's MOT history
An advisory is a tester's warning that something is wearing but has not failed yet. These are the ones written most often on the Mercedes-Benz CLA, per 1,000 tests. If the car you are looking at has one of these, ask whether it has been fixed since.
- Tread depth: worn close to legal limit/worn on edge283.2
- Tyres: slightly damaged/cracking or perishing112.5
- Brake discs: worn, pitted or scored, but not seriously weakened101.9
- Brake pads: wearing thin98.7
- Brake discs: worn, but not excessively54.5
- Tyres: has a cut but not deep enough to reach the ply or cords31.9
Checking a used Mercedes-Benz CLA before you buy
Against cars of the same age, the Mercedes-Benz CLA fails more often than average on tyres, seat belts and airbags and wheels. Start there.
Tyres
Check the tread across the full width of every tyre, inner edge included. Uneven wear points to worn suspension or out of line steering geometry.
Seat belts and airbags
Pull every seat belt out fully and let it retract, check each buckle latches, and make sure the airbag warning light goes out after starting.
Wheels
Look for damaged rims, missing wheel nuts and cracked alloys, particularly on the inside edge where kerb damage hides.
Averages only take you so far. The specific car's MOT history shows whether it has already failed on any of these, how often advisories were ignored, and whether the mileage climbs steadily from test to test. Read our guide to reading a car's MOT history before you go to view it.
Fuel mix of the Mercedes-Benz CLA cars tested: Petrol 56%, Diesel 37%, Hybrid 7%. Average age at test 6.6 years, average recorded mileage 59,700.
Mercedes-Benz CLA MOT questions
What is the Mercedes-Benz CLA MOT failure rate?
19.4% of Mercedes-Benz CLA cars failed their first MOT test of 2025, from 73,975 tests on vehicles aged 3 to 20. An average car with the same age mix failed 19.2% of the time, so the Mercedes-Benz CLA was about as likely to fail.
What fails most often on a Mercedes-Benz CLA MOT?
Tyres caused the most failure items, at 116 per 1,000 tests. The single most common failure item was "Tread depth below requirements of 1.6mm", recorded 30.6 times per 1,000 tests.
Which Mercedes-Benz CLA year has the best MOT record?
Measured against cars of the same age, 2013 registrations did best: 30.2% failed against an average of 34.3% for cars that age. Older cars always fail more often, so compare a year with its age group rather than with newer cars.
Does this tell me whether a particular Mercedes-Benz CLA will pass?
No. These are averages across every Mercedes-Benz CLA tested in 2025. The car in front of you has its own record: its full MOT history shows every pass, failure and advisory it has had, and it is free to view by registration.
Other Mercedes-Benz models
- Mercedes-Benz A-Class21.5% failed
- Mercedes-Benz C-Class24.8% failed
- Mercedes-Benz E-Class22.3% failed
- Mercedes-Benz GLA16.8% failed
- Mercedes-Benz GLC13.7% failed
- Mercedes-Benz Vito32.5% failed
Ranked close to the Mercedes-Benz CLA
- Peugeot 107rank 128
- Mazda 2rank 129
- Ford C-Maxrank 130
- Mazda 6rank 132
How these figures are calculated
Source: DVSA Anonymised MOT tests and results, 2025 release. We count first tests of cars and small vans (class 4) aged 3 to 20, so a car that fails and is retested is counted once. A failure includes faults fixed and passed within the same visit. The same age average weights the national failure rate for each age by how many Mercedes-Benz CLA cars of that age were tested, so a model is never penalised for having an older fleet. Make and model are as recorded at the test; trim levels are combined. Full method and rankings.
Contains public sector information licensed under the Open Government Licence v3.0.