2025 MOT results
Mercedes-Benz CLS-Class common problems
The most common reason a Mercedes-Benz CLS-Class fails its MOT is a broken coil spring, on 13.5% of its 5,678 failed tests in 2025. Against other cars of the same age, 5 faults stand out, the widest gaps being: corroded brake pipes at 7.6% of failures against 1.7% expected; a bulge in a tyre at 4.2% of failures against 1.4% expected; a tyre worn through to the cords at 12.1% of failures against 4.7% expected.
- Tests in 2025 22,322 Cars aged three and over
- Failed first time 25.4% 5,678 tests
- Found a dangerous defect 10.3% Unsafe to drive away
- Ended with an advisory 52.1% A problem to watch, not a failure
What fails a Mercedes-Benz CLS-Class MOT
Each bar is the share of failed Mercedes-Benz CLS-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 (11 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 |
|---|---|
| Coil spring: fractured or broken Suspension | 13.5% |
| Tyres: ply or cords exposed Tyres | 12.1% |
| Tyres: tread depth below requirements of 1.6mm Tyres | 10.4% |
| Malfunction indicator lamp: inoperative or indicates a malfunction Noise, emissions and leaks | 8.1% |
| Tyres: cut in excess of the requirements deep enough to reach the ply or cords Tyres | 7.7% |
| Rigid brake pipes: excessively corroded Brakes | 7.6% |
| Suspension arms: ball joint excessively worn Suspension | 6.9% |
| Road wheels: fractured Road wheels | 4.6% |
| Linkage ball joint dust cover no longer prevents the ingress of dirt Suspension | 4.4% |
| Tyres: tear, caused by separation or partial failure of its structure Tyres | 4.4% |
| Tyres: bulge, caused by separation or partial failure of its structure Tyres | 4.2% |
| Parking brake efficiency below requirements Brakes | 3.8% |
Source:DVSA,UK Motoring analysis 2025 Updated
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Broken coil spring
13.5% of failures 9.7% expected somewhat more 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.
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Tyre worn through to the cords
12.1% of failures 4.7% expected 2.6 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.
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Tyre worn below the legal limit
10.4% of failures 8.0% 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.
-
Engine management light on
8.1% of failures 5.5% expected 1.5 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.
-
Cut tyre
7.7% of failures 4.4% expected 1.8 times as 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.
-
Corroded brake pipes
7.6% of failures 1.7% expected 4.5 times as often
Corroded or damaged brake pipework. It is a safety item, and on older cars the rear pipes go first.
Look along the pipes under the sills with a torch; flaking rust rather than surface staining is the problem.
Which parts of the car fail
Tyres is the area that most often fails a Mercedes-Benz CLS-Class, on 37.0% of failed tests. That is also where it differs most from cars of the same registration years, which record 22.1%.
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 | 37.0% |
| Suspension | 34.4% |
| Brakes | 24.0% |
| Lamps, reflectors and electrical equipment | 19.6% |
| Noise, emissions and leaks | 11.6% |
| Visibility | 7.7% |
| Road wheels | 6.9% |
| Steering | 4.7% |
Source:DVSA,UK Motoring analysis 2025 Updated
What testers warn about
52.1% of Mercedes-Benz CLS-Class tests ended with at least one advisory: a fault the tester found that did not fail the test. On Mercedes-Benz CLS-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 | 19.8% |
| Rigid brake pipes: corroded, covered in grease or other material Brakes | 12.6% |
| Brake discs: worn, pitted or scored, but not seriously weakened Brakes | 8.3% |
| Brake pads: wearing thin Brakes | 7.6% |
| Engine oil leak, but not excessive Noise, emissions and leaks | 6.5% |
| Wheel bearings: slight play Suspension | 4.8% |
| Tyres: slightly damaged or cracking or perishing Tyres | 4.2% |
| Suspension arms: pin or bush worn but not resulting in excessive movement Suspension | 4.1% |
| Suspension arms: ball joint has slight play Suspension | 3.7% |
| Brake discs: worn, but not excessively Brakes | 3.5% |
| Tyres: cut but not deep enough to reach the ply or cords Tyres | 2.8% |
| Exhaust system: mounting defective Body, chassis, structure | 2.2% |
Source:DVSA,UK Motoring analysis 2025 Updated
Mercedes-Benz CLS-Class problems: common questions
What is the most common problem with a Mercedes-Benz CLS-Class?
Of the faults that fail an MOT, “Coil spring: fractured or broken” is the most common: it appears on 13.5% of failed Mercedes-Benz CLS-Class tests. Across categories, tyres is the area that most often fails one, on 37.0% of failed tests.
How often does a Mercedes-Benz CLS-Class fail its MOT?
25.4% of Mercedes-Benz CLS-Class tests in 2025 were not passed first time, from 22,322 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 55 out of 100, where 50 is as expected.
Does anything fail more often on a Mercedes-Benz CLS-Class than on other cars?
Yes. “Rigid brake pipes: excessively corroded” appears on 7.6% of its failures against 1.7% for cars of the same age, and “Tyres: bulge, caused by separation or partial failure of its structure” appears on 4.2% of its failures against 1.4% 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 CLS-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 | 22,322 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.