2025 MOT results
Mercedes-Benz GLC-Class common problems
The most common reason a Mercedes-Benz GLC-Class fails its MOT is a worn steering or suspension joint, on 20.5% of its 11,467 failed tests in 2025. Against other cars of the same age, 4 faults stand out, the widest gaps being: a worn steering or suspension joint at 20.5% of failures against 2.7% expected; a braking fault at 3.7% of failures against 1.0% expected; a split joint boot at 7.7% of failures against 2.2% expected.
- Tests in 2025 83,770 Cars aged three and over
- Failed first time 13.7% 11,467 tests
- Found a dangerous defect 4.1% Unsafe to drive away
- Ended with an advisory 38.8% A problem to watch, not a failure
What fails a Mercedes-Benz GLC-Class MOT
Each bar is the share of failed Mercedes-Benz GLC-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 |
|---|---|
| Suspension arms: ball joint excessively worn Suspension | 20.5% |
| Tyres: cut in excess of the requirements deep enough to reach the ply or cords Tyres | 13.7% |
| Tyres: tread depth below requirements of 1.6mm Tyres | 12.0% |
| Malfunction indicator lamp: inoperative or indicates a malfunction Noise, emissions and leaks | 10.1% |
| Tyres: ply or cords exposed Tyres | 8.7% |
| Drive shafts: constant velocity boot split or insecure, no longer prevents the ingress of dirt Body, chassis, structure | 7.7% |
| Brake pads: less than 1.5 mm thick Brakes | 6.2% |
| Coil spring: fractured or broken Suspension | 5.1% |
| Washers: provides insufficient washer liquid Visibility | 4.1% |
| Wipers: does not clear the windscreen effectively Visibility | 3.7% |
| Brake pads: worn down to wear indicator Brakes | 3.7% |
| Headlamp aim: too low Lamps, reflectors and electrical equipment | 3.2% |
Source:DVSA,UK Motoring analysis 2025 Updated
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Worn steering or suspension joint
20.5% of failures 2.7% expected 7.6 times as often
Play in a steering or suspension joint, where a worn ball and socket lets the wheel move where it should not.
A knock at low speed over rough ground, or vague steering, is the usual warning.
-
Cut tyre
13.7% of failures 9.3% expected 1.5 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.
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Tyre worn below the legal limit
12.0% of failures 10.4% 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
10.1% of failures 4.9% expected 2.1 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.
-
Tyre worn through to the cords
8.7% of failures 6.1% expected somewhat more 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.
-
Split joint boot
7.7% of failures 2.2% expected 3.5 times as often
A split rubber boot on a joint or driveshaft. The joint may still be sound, but dirt and water get in once the boot is open.
Turn the wheels to full lock and look behind them for greasy splits in the rubber concertina.
Which parts of the car fail
Tyres is the area that most often fails a Mercedes-Benz GLC-Class, on 38.4% of failed tests. The widest gap against cars of the same registration years is suspension, on 28.0% against 18.0% expected.
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 | 38.4% |
| Suspension | 28.0% |
| Brakes | 12.3% |
| Noise, emissions and leaks | 10.4% |
| Visibility | 10.3% |
| Body, chassis, structure | 9.2% |
| Lamps, reflectors and electrical equipment | 7.9% |
| Identification of the vehicle | 3.0% |
Source:DVSA,UK Motoring analysis 2025 Updated
What testers warn about
38.8% of Mercedes-Benz GLC-Class tests ended with at least one advisory: a fault the tester found that did not fail the test. On Mercedes-Benz GLC-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 | 18.1% |
| Brake pads: wearing thin Brakes | 8.0% |
| Suspension arms: ball joint has slight play Suspension | 6.2% |
| Brake discs: worn, pitted or scored, but not seriously weakened Brakes | 4.9% |
| Tyres: slightly damaged or cracking or perishing Tyres | 4.5% |
| Brake discs: worn, but not excessively Brakes | 3.7% |
| Child seat fitted not allowing full inspection of adult belt Non-component advisories | 2.9% |
| Nail in tyre Non-component advisories | 2.1% |
| Tyres: cut but not deep enough to reach the ply or cords Tyres | 1.8% |
| Registration plates: deteriorated but not likely to be misread Identification of the vehicle | 1.2% |
| Tyres: slightly damaged Tyres | 0.6% |
| Items removed from driver's view prior to test Non-component advisories | 0.5% |
Source:DVSA,UK Motoring analysis 2025 Updated
What changes as a Mercedes-Benz GLC-Class gets older
A 2022 Mercedes-Benz GLC-Class failed 8.9% of its MOT tests in 2025; a 2016 one failed 17.2%. What fails changes as much as how often, and these are the two years themselves rather than an average across them.
2022 Mercedes-Benz GLC-Class 8.9% failed, from 7,130 tests
- Cut tyre 32.5%
- Tyre worn through to the cords 16.3%
- Tyre worn below the legal limit 13.9%
- Wiper blades that do not clear the screen 9.0%
- Braking fault 3.8%
- Headlamp aim set too low 3.8%
2016 Mercedes-Benz GLC-Class 17.2% failed, from 9,081 tests
- Worn steering or suspension joint 23.5%
- Broken coil spring 13.0%
- Engine management light on 11.7%
- Tyre worn below the legal limit 11.5%
- Split joint boot 8.6%
- Cut tyre 7.7%
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 GLC-Class problems: common questions
What is the most common problem with a Mercedes-Benz GLC-Class?
Of the faults that fail an MOT, “Suspension arms: ball joint excessively worn” is the most common: it appears on 20.5% of failed Mercedes-Benz GLC-Class tests. Across categories, tyres is the area that most often fails one, on 38.4% of failed tests.
How often does a Mercedes-Benz GLC-Class fail its MOT?
13.7% of Mercedes-Benz GLC-Class tests in 2025 were not passed first time, from 83,770 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 64 out of 100, where 50 is as expected.
Does anything fail more often on a Mercedes-Benz GLC-Class than on other cars?
Yes. “Suspension arms: ball joint excessively worn” appears on 20.5% of its failures against 2.7% for cars of the same age, and “Brake pads: worn down to wear indicator” appears on 3.7% 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 GLC-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 | 83,770 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.