2025 MOT results
Mercedes-Benz SLC-Class common problems
The most common reason a Mercedes-Benz SLC-Class fails its MOT is a tyre worn through to the cords, on 15.1% of its 1,340 failed tests in 2025. Against other cars of the same age, 7 faults stand out, the widest gaps being: a lighting fault at 5.0% of failures against 0.6% expected; a split joint boot at 3.4% of failures against 1.2% expected; a tyre worn through to the cords at 15.1% of failures against 5.4% expected.
- Tests in 2025 8,983 Cars aged three and over
- Failed first time 14.9% 1,340 tests
- Found a dangerous defect 5.3% Unsafe to drive away
- Ended with an advisory 32.9% A problem to watch, not a failure
What fails a Mercedes-Benz SLC-Class MOT
Each bar is the share of failed Mercedes-Benz SLC-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 |
|---|---|
| Tyres: ply or cords exposed Tyres | 15.1% |
| Tyres: cut in excess of the requirements deep enough to reach the ply or cords Tyres | 12.9% |
| Coil spring: fractured or broken Suspension | 12.8% |
| Tyres: tread depth below requirements of 1.6mm Tyres | 9.0% |
| Suspension arms: ball joint excessively worn Suspension | 8.6% |
| Malfunction indicator lamp: inoperative or indicates a malfunction Noise, emissions and leaks | 6.6% |
| Anti-lock braking system: warning lamp indicates an ABS fault Brakes | 5.0% |
| Road wheels: fractured Road wheels | 3.7% |
| Tyres: tear, caused by separation or partial failure of its structure Tyres | 3.7% |
| Headlamp aim: too low Lamps, reflectors and electrical equipment | 3.7% |
| Suspension arms: ball joint dust cover no longer prevents the ingress of dirt Suspension | 3.6% |
| Linkage ball joint dust cover no longer prevents the ingress of dirt Suspension | 3.4% |
Source:DVSA,UK Motoring analysis 2025 Updated
-
Tyre worn through to the cords
15.1% of failures 5.4% expected 2.8 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.
-
Cut tyre
12.9% of failures 7.1% 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.
-
Broken coil spring
12.8% of failures 7.9% 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.
-
Tyre worn below the legal limit
9.0% of failures 9.9% expected about as expected
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.
-
Worn steering or suspension joint
8.6% of failures 3.6% expected 2.4 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.
-
Engine management light on
6.6% of failures 5.4% expected somewhat more 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.
Which parts of the car fail
Tyres is the area that most often fails a Mercedes-Benz SLC-Class, on 43.3% of failed tests. That is also where it differs most from cars of the same registration years, which record 29.9%.
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 | 43.3% |
| Suspension | 31.3% |
| Lamps, reflectors and electrical equipment | 12.8% |
| Brakes | 10.4% |
| Noise, emissions and leaks | 9.6% |
| Road wheels | 4.9% |
| Visibility | 4.0% |
| Identification of the vehicle | 2.4% |
Source:DVSA,UK Motoring analysis 2025 Updated
What testers warn about
32.9% of Mercedes-Benz SLC-Class tests ended with at least one advisory: a fault the tester found that did not fail the test. On Mercedes-Benz SLC-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 | 15.3% |
| Tyres: slightly damaged or cracking or perishing Tyres | 7.2% |
| Tyres: cut but not deep enough to reach the ply or cords Tyres | 3.6% |
| Brake discs: worn, pitted or scored, but not seriously weakened Brakes | 3.5% |
| Wheel bearings: slight play Suspension | 2.6% |
| Brake pads: wearing thin Brakes | 2.6% |
| Tyres: slightly damaged Tyres | 2.0% |
| Brake discs: worn, but not excessively Brakes | 1.9% |
| Road wheels: slightly distorted Road wheels | 1.6% |
| Nail in tyre Non-component advisories | 1.5% |
| Shock absorbers: light misting of oil Suspension | 0.8% |
| Registration plates: deteriorated but not likely to be misread Identification of the vehicle | 0.7% |
Source:DVSA,UK Motoring analysis 2025 Updated
Mercedes-Benz SLC-Class problems: common questions
What is the most common problem with a Mercedes-Benz SLC-Class?
Of the faults that fail an MOT, “Tyres: ply or cords exposed” is the most common: it appears on 15.1% of failed Mercedes-Benz SLC-Class tests. Across categories, tyres is the area that most often fails one, on 43.3% of failed tests.
How often does a Mercedes-Benz SLC-Class fail its MOT?
14.9% of Mercedes-Benz SLC-Class tests in 2025 were not passed first time, from 8,983 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 54 out of 100, where 50 is as expected.
Does anything fail more often on a Mercedes-Benz SLC-Class than on other cars?
Yes. “Anti-lock braking system: warning lamp indicates an ABS fault” appears on 5.0% of its failures against 0.6% for cars of the same age, and “Linkage ball joint dust cover no longer prevents the ingress of dirt” appears on 3.4% of its failures against 1.2% 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 SLC-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 | 8,983 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.