2025 MOT results
Mercedes-Benz SL-Class common problems
The most common reason a Mercedes-Benz SL-Class fails its MOT is a broken coil spring, on 7.1% of its 3,548 failed tests in 2025. Against other cars of the same age, 5 faults stand out, the widest gaps being: a split joint boot at 6.3% of failures against 2.3% expected; a cut tyre at 6.5% of failures against 2.9% expected; a torn tyre at 4.5% of failures against 2.2% expected.
- Tests in 2025 20,771 Cars aged three and over
- Failed first time 17.1% 3,548 tests
- Found a dangerous defect 4.4% Unsafe to drive away
- Ended with an advisory 40.2% A problem to watch, not a failure
What fails a Mercedes-Benz SL-Class MOT
Each bar is the share of failed Mercedes-Benz SL-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 |
|---|---|
| Coil spring: fractured or broken Suspension | 7.1% |
| Suspension arms: ball joint excessively worn Suspension | 6.8% |
| Tyres: cut in excess of the requirements deep enough to reach the ply or cords Tyres | 6.5% |
| Tyres: ply or cords exposed Tyres | 6.5% |
| Suspension arms: ball joint dust cover no longer prevents the ingress of dirt Suspension | 6.3% |
| Wipers: does not clear the windscreen effectively Visibility | 5.2% |
| Malfunction indicator lamp: inoperative or indicates a malfunction Noise, emissions and leaks | 4.6% |
| Tyres: tear, caused by separation or partial failure of its structure Tyres | 4.5% |
| Rigid brake pipes: excessively corroded Brakes | 4.1% |
| Headlamp aim: too low Lamps, reflectors and electrical equipment | 4.0% |
| Tyres: tread depth below requirements of 1.6mm Tyres | 3.6% |
| SRS malfunction indicator lamp: warning lamp indicates a fault Seat belts and supplementary restraint systems | 3.6% |
Source:DVSA,UK Motoring analysis 2025 Updated
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Broken coil spring
7.1% of failures 6.5% expected about as expected
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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Worn steering or suspension joint
6.8% of failures 4.8% expected somewhat more 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
6.5% of failures 2.9% expected 2.2 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 through to the cords
6.5% of failures 3.4% expected 1.9 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.
-
Split joint boot
6.3% of failures 2.3% expected 2.7 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.
-
Wiper blades that do not clear the screen
5.2% of failures 6.8% expected somewhat less often
Wiper blades that leave the windscreen smeared or streaked across the area the driver looks through.
Look for split or hardened rubber, and lift each blade to see whether it still sits flat.
Which parts of the car fail
Suspension is the area that most often fails a Mercedes-Benz SL-Class, on 29.8% of failed tests. The widest gap against cars of the same registration years is tyres, on 24.9% against 15.8% 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 |
|---|---|
| Suspension | 29.8% |
| Lamps, reflectors and electrical equipment | 27.9% |
| Tyres | 24.9% |
| Brakes | 19.7% |
| Visibility | 13.0% |
| Noise, emissions and leaks | 11.6% |
| Body, chassis, structure | 5.6% |
| Seat belts and supplementary restraint systems | 4.2% |
Source:DVSA,UK Motoring analysis 2025 Updated
What testers warn about
40.2% of Mercedes-Benz SL-Class tests ended with at least one advisory: a fault the tester found that did not fail the test. On Mercedes-Benz SL-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 | 9.2% |
| Rigid brake pipes: corroded, covered in grease or other material Brakes | 8.7% |
| Tyres: slightly damaged or cracking or perishing Tyres | 7.2% |
| Engine oil leak, but not excessive Noise, emissions and leaks | 6.1% |
| Brake discs: worn, pitted or scored, but not seriously weakened Brakes | 5.4% |
| Brake pads: wearing thin Brakes | 3.6% |
| Suspension arms: ball joint has slight play Suspension | 3.6% |
| Wheel bearings: slight play Suspension | 2.6% |
| Flexible brake hoses: slightly deteriorated Brakes | 2.0% |
| Shock absorbers: light misting of oil Suspension | 1.9% |
| Suspension arms: pin or bush worn but not resulting in excessive movement Suspension | 1.9% |
| Tyres: cut but not deep enough to reach the ply or cords Tyres | 1.7% |
Source:DVSA,UK Motoring analysis 2025 Updated
Mercedes-Benz SL-Class problems: common questions
What is the most common problem with a Mercedes-Benz SL-Class?
Of the faults that fail an MOT, “Coil spring: fractured or broken” is the most common: it appears on 7.1% of failed Mercedes-Benz SL-Class tests. Across categories, suspension is the area that most often fails one, on 29.8% of failed tests.
How often does a Mercedes-Benz SL-Class fail its MOT?
17.1% of Mercedes-Benz SL-Class tests in 2025 were not passed first time, from 20,771 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 73 out of 100, where 50 is as expected.
Does anything fail more often on a Mercedes-Benz SL-Class than on other cars?
Yes. “Suspension arms: ball joint dust cover no longer prevents the ingress of dirt” appears on 6.3% of its failures against 2.3% for cars of the same age, and “Tyres: cut in excess of the requirements deep enough to reach the ply or cords” appears on 6.5% of its failures against 2.9% 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 SL-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 | 20,771 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.