Is the Mercedes-Benz CLS reliable?

On MOT evidence the Mercedes-Benz CLS is above average. It passes 76.4% of tests once age and mileage are accounted for, against a national average of 72.3%, which ranks it 93 of 262 models with enough data for a fair comparison. This measures how often the car meets the MOT standard, not how often it breaks down or what a repair costs.

What is the most common MOT failure on a Mercedes-Benz CLS?

The item recorded most often is "A spring or spring component fractured or seriously weakened", which appears in 18.4% of failed Mercedes-Benz CLS tests. Because one failed test can list several items, these shares do not add up to 100%.

What do testers most often warn about on a Mercedes-Benz CLS?

The most common advisory is "Tyre tread depth not in accordance with the requirements", noted on 26.7% of all Mercedes-Benz CLS tests. An advisory is not a failure: it flags something that will likely need attention before the next test.

What mileage does a Mercedes-Benz CLS usually have at its MOT?

The average odometer reading recorded at test is 95,277 miles. This is the mileage across all tested examples of every age, not an annual figure, so treat it as a description of the fleet rather than a target for one car.

Does a Mercedes-Benz CLS get harder to pass as it ages?

Yes. At 3 to 5 years old, 79.6% of Mercedes-Benz CLS tests pass. By fifteen years or more, that falls to 68.3%. Nearly every model follows this pattern, which is why comparing raw pass rates between models is misleading unless age is accounted for.

Are most Mercedes-Benz CLS models petrol or diesel?

Of the Mercedes-Benz CLS cars tested, 88% are diesel, 11% are petrol, 1% are hybrid. Fuel type affects which items tend to fail, particularly emissions and exhaust components.

Model reliability file

Mercedes-Benz CLS MOT pass rate & common failures

From 22,073 recorded MOT tests of the Mercedes-Benz CLS, published by DVSA.

Data updated 29 July 2026

Quick answer

The Mercedes-Benz CLS passes 76.4% of MOT tests once results are adjusted for the age and mileage of the cars tested, against a national average of 72.3%. That is above average, ranking it 93 of 262 models with enough data to compare fairly. Based on 22,073 tests. Its most commonly recorded failure is spring or spring component fractured or seriously weakened, which appears in 18.4% of failed tests. Cars of this model average 95,277 miles on the odometer when tested.

At a glance

Pass rate, adjusted for age and mileage

76.4%national average72.3%unadjusted74.5%range covered90%rank93 of 262

The CLS is 4.1 percentage points above the national pass rate once age and mileage are accounted for, which is above average. The unadjusted figure is 74.5%; the difference is what the age and mileage of this model’s fleet was hiding.

DVSA recorded wording

Most common failure items

Share of failed Mercedes-Benz CLS tests in which each item was recorded. One failed test often lists several items, so these do not sum to 100%.

1.A spring or spring component fractured or seriously weakened18.4%
911 occurrencesRoad spring broken or fractured explained
2.A tyre cords visible or damaged16.8%
832 occurrencesTyre ply or cord exposed, or the casing separating explained
3.Tyre tread depth not in accordance with the requirements16.4%
810 occurrencesTyre worn close to the legal limit explained
4.Brake pipe damaged or excessively corroded14.5%
718 occurrencesBrake pipe corroded explained
5.A tyre seriously damaged10.3%
510 occurrencesTyre damaged or deteriorated explained
6.A suspension pin, bush or joint excessively worn10.1%
499 occurrencesSuspension arm bush worn explained
7.A suspension joint dust cover missing or no longer prevents the ingress of dirt etc6.2%
305 occurrencesSuspension joint dust cover missing or split explained
8.A tyre seriously damaged6.1%
301 occurrencesTyre damaged or deteriorated explained
9.Any fracture or welding defect on a wheel6.1%
301 occurrencesRoad wheel damaged, distorted or cracked explained
10.A tyre seriously damaged5.1%
255 occurrencesTyre damaged or deteriorated explained

Warnings without a failure

Most common advisories

Share of all Mercedes-Benz CLS tests carrying each advisory. The denominator differs from the failure list above because an advisory can be issued on a car that passed.

1.Tyre tread depth not in accordance with the requirements26.7%
5,886 testsTyre worn close to the legal limit explained
2.Brake pipe damaged or excessively corroded21.0%
4,629 testsBrake pipe corroded explained
3.Brake disc or drum excessively weakened, insecure or fractured11.7%
2,582 testsBrake disc worn, pitted or scored explained
4.A brake lining or pad worn below 1.5mm9.6%
2,115 testsBrake drum or shoe worn or contaminated explained
5.A wheel bearing with excessive play6.8%
1,495 testsWheel bearing has excessive play or is rough explained
6.Fluid leaking excessively and likely to harm the environment or to pose a safety risk to other road users6.6%
1,457 tests
7.A suspension pin, bush or joint excessively worn6.1%
1,340 testsSuspension arm bush worn explained
8.A tyre seriously damaged5.9%
1,300 testsTyre damaged or deteriorated explained

How wear changes the picture

Pass rate by vehicle age

3–5 yrs80%

6–8 yrs81%

9–11 yrs78%

12–14 yrs73%

15+ yrs68%

Bands holding too few tests to be meaningful are omitted rather than shown as a rate.

What gets tested

The CLS fleet

Average mileage recorded at test: 95,277
Fuel mix of tested cars: Diesel88.5%
Petrol10.9%
Hybrid0.6%

Trim names grouped into this model (12)

Recorded exactly as DVSA holds them. Trim-level names are rolled up so one model is not split across a dozen thin pages.

CLS 220 D
CLS 220 SPORT PREMIUM + D AUTO
CLS 250 CDI
CLS 300 D AMG LINE AUTO
CLS 320 CDI
CLS 320D
CLS 350
CLS 350 BLUE EFFICIENCY AUTO
CLS 350 CDI
CLS 450
CLS 55
CLS 550 AUTO

Check a specific Mercedes-Benz CLS

A model average tells you the pattern. Its own MOT record tells you the car.

Compare within the range

Other Mercedes-Benz models

Mercedes-Benz A-Class — 73.3% adjusted
Mercedes-Benz C-Class — 77.0% adjusted
Mercedes-Benz E-Class — 78.5% adjusted
Mercedes-Benz GLA — 82.3% adjusted
Mercedes-Benz Vito — 71.0% adjusted
Mercedes-Benz GLC — 85.9% adjusted
All Mercedes-Benz models

Similar test volumes

Compare against other makes

Mini John Cooper Works — 83.8% adjusted, ranked 27
Jaguar XJ — 79.9% adjusted, ranked 57
Smart (mcc) Forfour — 64.8% adjusted, ranked 223
BMW 6 Series — 81.4% adjusted, ranked 46

Common questions

Is the Mercedes-Benz CLS reliable?: On MOT evidence the Mercedes-Benz CLS is above average. It passes 76.4% of tests once age and mileage are accounted for, against a national average of 72.3%, which ranks it 93 of 262 models with enough data for a fair comparison. This measures how often the car meets the MOT standard, not how often it breaks down or what a repair costs.
What is the most common MOT failure on a Mercedes-Benz CLS?: The item recorded most often is "A spring or spring component fractured or seriously weakened", which appears in 18.4% of failed Mercedes-Benz CLS tests. Because one failed test can list several items, these shares do not add up to 100%.
What do testers most often warn about on a Mercedes-Benz CLS?: The most common advisory is "Tyre tread depth not in accordance with the requirements", noted on 26.7% of all Mercedes-Benz CLS tests. An advisory is not a failure: it flags something that will likely need attention before the next test.
What mileage does a Mercedes-Benz CLS usually have at its MOT?: The average odometer reading recorded at test is 95,277 miles. This is the mileage across all tested examples of every age, not an annual figure, so treat it as a description of the fleet rather than a target for one car.
Does a Mercedes-Benz CLS get harder to pass as it ages?: Yes. At 3 to 5 years old, 79.6% of Mercedes-Benz CLS tests pass. By fifteen years or more, that falls to 68.3%. Nearly every model follows this pattern, which is why comparing raw pass rates between models is misleading unless age is accounted for.
Are most Mercedes-Benz CLS models petrol or diesel?: Of the Mercedes-Benz CLS cars tested, 88% are diesel, 11% are petrol, 1% are hybrid. Fuel type affects which items tend to fail, particularly emissions and exhaust components.

How this was worked out

Method and limits

Figures come from the DVSA anonymised MOT testing dataset, published under the Open Government Licence. Only class 4 initial tests are counted: retests are excluded so a car appears once, and abandoned tests are excluded entirely. The adjusted rate is directly standardised across twenty-five age and mileage bands and reweighted onto the national distribution, so this model is compared against cars that have lived a similar life rather than against a younger or lighter-used fleet.

An MOT measures whether a car met a legal standard on the day. It is not a breakdown record, a service history or a running-cost estimate, and a pass rate is a property of a fleet rather than a prediction about one car.