2025 MOT results
Mercedes-Benz CLA-Class common problems
The most common reason a Mercedes-Benz CLA-Class fails its MOT is a cut tyre, on 12.2% of its 14,385 failed tests in 2025. Against other cars of the same age, 6 faults stand out, the widest gaps being: a split joint boot at 5.3% of failures against 1.2% expected; the airbag light on at 4.4% of failures against 1.0% expected; the engine management light on at 9.0% of failures against 4.7% expected.
- Tests in 2025 74,291 Cars aged three and over
- Failed first time 19.4% 14,385 tests
- Found a dangerous defect 7.7% Unsafe to drive away
- Ended with an advisory 41.2% A problem to watch, not a failure
What fails a Mercedes-Benz CLA-Class MOT
Each bar is the share of failed Mercedes-Benz CLA-Class tests with that defect. Where we can compare it with cars of the same registration years, the marker shows what an average car of those ages records (12 of the 12 items below).
Most common reasons for failure
A test can fail for more than one defect, so shares add up to more than 100%.
| Defect | Share of failed tests |
|---|---|
| Tyres: cut in excess of the requirements deep enough to reach the ply or cords Tyres | 12.2% |
| Tyres: tread depth below requirements of 1.6mm Tyres | 12.1% |
| Tyres: ply or cords exposed Tyres | 11.2% |
| Coil spring: fractured or broken Suspension | 10.5% |
| Malfunction indicator lamp: inoperative or indicates a malfunction Noise, emissions and leaks | 9.0% |
| Brake pads: less than 1.5 mm thick Brakes | 8.5% |
| Washers: provides insufficient washer liquid Visibility | 6.5% |
| Linkage ball joint dust cover no longer prevents the ingress of dirt Suspension | 5.3% |
| Wipers: does not clear the windscreen effectively Visibility | 4.9% |
| SRS malfunction indicator lamp: warning lamp indicates a fault Seat belts and supplementary restraint systems | 4.4% |
| Tyres: bulge, caused by separation or partial failure of its structure Tyres | 4.2% |
| Headlamp aim: too low Lamps, reflectors and electrical equipment | 4.0% |
Source:DVSA,UK Motoring analysis 2025 Updated
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Cut tyre
12.2% of failures 9.1% expected somewhat more often
A cut in the tyre deep or long enough to reach the structure underneath, usually from a kerb or debris.
Run a hand round the inner and outer walls of each tyre, which is where kerbing shows.
-
Tyre worn below the legal limit
12.1% of failures 9.9% expected somewhat more often
A tyre worn past the 1.6mm legal minimum across the middle three quarters of the tread.
A 20p coin in the main grooves: if the outer band of the coin is visible, the tyre is close to the limit.
-
Tyre worn through to the cords
11.2% of failures 6.2% expected 1.8 times as often
The tyre is worn or damaged far enough to expose the cords underneath, which is a dangerous defect.
Run a hand round the inner and outer walls of each tyre, which is where kerbing shows.
-
Broken coil spring
10.5% of failures 6.5% expected 1.6 times as often
A broken suspension spring, which usually snaps in the bottom coil and often fails on both sides within a year.
Look at each corner for a sagging ride height, and listen for a knock over speed bumps.
-
Engine management light on
9.0% of failures 4.7% expected 1.9 times as often
The engine management light is on, or has been disconnected. Either fails the test.
A cheap code reader on the diagnostic socket will say what the car has stored before you pay for a test.
-
Worn brake pads
8.5% of failures 8.3% expected about as expected
Friction material worn under 1.5mm, thinner than the point most manufacturers call the limit.
Look through the wheel spokes at the pad against the disc; wear indicators squeal before they get this far.
Which parts of the car fail
Tyres is the area that most often fails a Mercedes-Benz CLA-Class, on 43.1% of failed tests. That is also where it differs most from cars of the same registration years, which record 32.3%.
Failure categories
DVSA's own sections of the test. The marker is what cars of the same registration years record.
| Defect category | Share of failed tests |
|---|---|
| Tyres | 43.1% |
| Suspension | 21.7% |
| Lamps, reflectors and electrical equipment | 16.2% |
| Brakes | 15.5% |
| Visibility | 14.5% |
| Noise, emissions and leaks | 10.1% |
| Seat belts and supplementary restraint systems | 5.2% |
| Road wheels | 4.4% |
Source:DVSA,UK Motoring analysis 2025 Updated
What testers warn about
41.2% of Mercedes-Benz CLA-Class tests ended with at least one advisory: a fault the tester found that did not fail the test. On Mercedes-Benz CLA-Classes, these are the items to ask about on a car you are viewing, because they are what the last tester expected to go next.
Most common advisories
Share of all tests, passes included.
| Advisory | Share of tests |
|---|---|
| Tread depth: worn close to legal limit or worn on edge Tyres | 19.2% |
| Brake pads: wearing thin Brakes | 8.1% |
| Tyres: slightly damaged or cracking or perishing Tyres | 7.7% |
| Brake discs: worn, pitted or scored, but not seriously weakened Brakes | 7.2% |
| Brake discs: worn, but not excessively Brakes | 3.9% |
| Tyres: cut but not deep enough to reach the ply or cords Tyres | 2.7% |
| Child seat fitted not allowing full inspection of adult belt Non-component advisories | 2.1% |
| Nail in tyre Non-component advisories | 2.0% |
| Tyres: slightly damaged Tyres | 1.3% |
| Suspension arms: ball joint has slight play Suspension | 1.1% |
| Road wheels: slightly distorted Road wheels | 1.1% |
| Linkage ball joint has slight play Suspension | 0.9% |
Source:DVSA,UK Motoring analysis 2025 Updated
What changes as a Mercedes-Benz CLA-Class gets older
A 2022 Mercedes-Benz CLA-Class failed 12.7% of its MOT tests in 2025; a 2013 one failed 30.2%. What fails changes as much as how often, and these are the two years themselves rather than an average across them.
2022 Mercedes-Benz CLA-Class 12.7% failed, from 11,292 tests
- Cut tyre 25.2%
- Tyre worn through to the cords 14.6%
- Tyre worn below the legal limit 12.4%
- Worn brake pads 7.5%
- Wiper blades that do not clear the screen 7.4%
- Headlamp aim set too high 5.4%
2013 Mercedes-Benz CLA-Class 30.2% failed, from 2,078 tests
- Broken coil spring 22.1%
- Engine management light on 13.9%
- Split joint boot 11.1%
- Tyre worn through to the cords 9.6%
- Washers that do not work 8.3%
- Airbag light on 7.6%
Shares are of each year's failed tests. Every MOT a particular car has had, with the defects and advisories written at each test, is on GOV.UK's MOT history service from the registration, free.
Mercedes-Benz CLA-Class problems: common questions
What is the most common problem with a Mercedes-Benz CLA-Class?
Of the faults that fail an MOT, “Tyres: cut in excess of the requirements deep enough to reach the ply or cords” is the most common: it appears on 12.2% of failed Mercedes-Benz CLA-Class tests. Across categories, tyres is the area that most often fails one, on 43.1% of failed tests.
How often does a Mercedes-Benz CLA-Class fail its MOT?
19.4% of Mercedes-Benz CLA-Class tests in 2025 were not passed first time, from 74,291 tests of cars aged three and over. Allowing for the age and mileage of the cars tested, that gives it a UK Motoring Reliability Score of 47 out of 100, where 50 is as expected.
Does anything fail more often on a Mercedes-Benz CLA-Class than on other cars?
Yes. “Linkage ball joint dust cover no longer prevents the ingress of dirt” appears on 5.3% of its failures against 1.2% for cars of the same age, and “SRS malfunction indicator lamp: warning lamp indicates a fault” appears on 4.4% of its failures against 1.0% for cars of the same age. Where an item is missing from the national figures for a year, we use the smallest share those figures show, so the comparison never overstates the difference.
Are these the same as breakdowns or known faults?
No. These are the items a tester recorded at the MOT, which covers condition and safety: lamps, brakes, tyres, suspension, corrosion and emissions. A gearbox that is unpleasant, an infotainment screen that has died, or a car that will not start on a cold morning are not part of the test, so they are not in these figures.
Where do the figures come from?
Every normal MOT test of a Mercedes-Benz CLA-Class aged three and over in Great Britain in 2025, from DVSA's anonymised MOT results. Retests are excluded, and the same fault on more than one wheel counts once.
Data stories to read next
Data sources and methodology
| Figures | Source | Period | Records | Updated |
|---|---|---|---|---|
| MOT defects and advisories | Anonymised MOT tests and results Driver and Vehicle Standards Agency Derived statistics UK Motoring | 2025 | 74,291 MOT tests | 19 September 2026 |
- Shares for defects are of failed tests; shares for advisories are of all tests. A test can carry several defects, so shares add to more than 100%.
- The expected share is what an average car of the same registration years records, weighted by where this model’s failures fall. Where an item is outside the national figures for a year, the smallest share those figures show is used in its place, which is an upper bound, so the comparison never overstates a model’s problems. No expectation is published where less than 80% of the model’s failures can be compared.
- Great Britain only: DVSA does not run MOT testing in Northern Ireland. Cars under three years old are not tested.
- The descriptions of what each part does are general and the same on every model. Every figure comes from the MOT data.
Contains public sector information licensed under the Open Government Licence v3.0.