Mercedes-Benz CLA MOT pass rate & common failures

At a glance

Pass rate, adjusted for age and mileage

The CLA is 6.3 percentage points above the national pass rate once age and mileage are accounted for, which is well above average. The unadjusted figure is 80.8%; 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 CLA tests in which each item was recorded. One failed test often lists several items, so these do not sum to 100%.

1. 1.Tyre tread depth not in accordance with the requirements17.6%

   2,187 occurrencesTyre worn close to the legal limit explained

2. 2.A tyre seriously damaged16.7%

   2,074 occurrencesTyre damaged or deteriorated explained

3. 3.A tyre cords visible or damaged16.5%

   2,042 occurrencesTyre ply or cord exposed, or the casing separating explained

4. 4.A spring or spring component fractured or seriously weakened13.4%

   1,655 occurrencesRoad spring broken or fractured explained

5. 5.A brake lining or pad worn below 1.5mm11.2%

   1,392 occurrencesBrake drum or shoe worn or contaminated explained

6. 6.A suspension joint dust cover missing or no longer prevents the ingress of dirt etc8.3%

   1,028 occurrencesSuspension joint dust cover missing or split explained

7. 7.Wiper blade missing or obviously not clearing the windscreen5.6%

   694 occurrencesWiper or washer not working properly explained

8. 8.A tyre seriously damaged5.3%

   661 occurrencesTyre damaged or deteriorated explained

9. 9.Windscreen washers not working or not providing sufficient fluid to clear the windscreen5.2%

   648 occurrencesWiper or washer not working properly explained

10. 10.A tyre seriously damaged4.5%

    560 occurrencesTyre damaged or deteriorated explained

Warnings without a failure

Most common advisories

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

1. 1.Tyre tread depth not in accordance with the requirements24.3%

   18,504 testsTyre worn close to the legal limit explained

2. 2.A tyre seriously damaged11.1%

   8,437 testsTyre damaged or deteriorated explained

3. 3.Brake disc or drum excessively weakened, insecure or fractured10.0%

   7,617 testsBrake disc worn, pitted or scored explained

4. 4.A brake lining or pad worn below 1.5mm9.8%

   7,450 testsBrake drum or shoe worn or contaminated explained

5. 5.Brake disc or drum significantly and obviously worn5.3%

   4,069 testsBrake disc worn, pitted or scored explained

6. 6.Tyre tread depth not in accordance with the requirements3.8%

   2,923 testsTyre worn close to the legal limit explained

7. 7.A tyre seriously damaged3.2%

   2,429 testsTyre damaged or deteriorated explained

8. 8.Child Seat fitted not allowing full inspection of adult belt2.3%

   1,731 tests

The rest of the record

Everything else recorded on the Mercedes-Benz CLA

The 22 other defects testers recorded on this model, beyond the most common listed above. Each links to what it means and what it takes to put right.

• Engine management light on, or not working4.5%
• Airbag warning lamp on, or airbag missing4.4%
• Registration plate missing, insecure or illegible2.8%
• Road wheel damaged, distorted or cracked2.8%
• Tyre pressure monitoring system inoperative2.5%
• Wheel nut, bolt or stud missing, loose or damaged2.4%
• Suspension arm bush worn2.3%
• Headlamp not working1.9%
• Direction indicator not working1.8%
• Driveshaft CV joint gaiter split or missing1.8%
• Headlamp aim incorrect1.5%
• Lamp of the wrong colour, position or intensity1.2%
• Brake pipe corroded0.8%
• Lamp not working0.7%
• Parking brake efficiency too low0.7%
• Ball joint worn0.3%
• Brake binding or imbalanced across an axle0.2%
• Shock absorber defective0.2%
• Brake fluid level below minimum0.1%
• Wheel bearing has excessive play or is rough0.1%
• Exhaust leaking or insecure0.1%
• Mirror missing, damaged or insecure0.1%

How wear changes the picture

CLA pass rate by age and registration year

How often the Mercedes-Benz CLA passes at each age, with the years those cars were first registered. Tests are from 2025, so a car aged 3 to 5 was first used in 2020–2022.

Read this as an age curve rather than a verdict on particular model years. Nearly every car passes less often as it gets older, so a newer CLA outscoring an older one says more about wear than about how that year’s cars were built. Bands holding too few tests to be meaningful are omitted rather than shown as a rate.

What gets tested

The CLA fleet

Average mileage recorded at test

58,902

Across examples of every age, so this is a description of the fleet rather than an annual figure.

Fuel mix of tested cars

Petrol57.1%

Diesel36.4%

Hybrid6.5%

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

• Mitsubishi Outlander — 73.8% adjusted, ranked 124
• Toyota Hilux — 71.2% adjusted, ranked 158
• Peugeot 108 — 78.6% adjusted, ranked 65
• Skoda Yeti — 72.3% adjusted, ranked 143

Common questions

Is the Mercedes-Benz CLA reliable?

On MOT evidence the Mercedes-Benz CLA is well above average. It passes 78.6% of tests once age and mileage are accounted for, against a national average of 72.3%. That figure covers 77% of the national age and mileage range, which is enough to quote but not to rank. 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 CLA?

The item recorded most often is "Tyre tread depth not in accordance with the requirements", which appears in 17.6% of failed Mercedes-Benz CLA 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 CLA?

The most common advisory is "Tyre tread depth not in accordance with the requirements", noted on 24.3% of all Mercedes-Benz CLA 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 CLA usually have at its MOT?

The average odometer reading recorded at test is 58,902 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.

Which Mercedes-Benz CLA years are the most reliable?

Going by MOT pass rate, Mercedes-Benz CLA cars first registered 2020–2022 do best at 86.0%, and those registered 2011–2013 do worst at 69.9%. But that ordering is mostly age, not build year: almost every model passes less often as it wears, so the newest cars top this list whatever they are. A specific year looking strong here means little on its own; the failure items above, and the individual car's own MOT history, tell you far more.

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

Yes. At 3 to 5 years old, 86.0% of Mercedes-Benz CLA tests pass. By 12 to 14 years, that falls to 69.9%. 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 CLA models petrol or diesel?

Of the Mercedes-Benz CLA cars tested, 57% are petrol, 36% are diesel, 7% 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.

Further reading

Make sense of the numbers

• How to judge reliability from evidence rather than reputation
• What counts as high or low mileage for a car’s age
• The most common MOT failures and how to avoid them
• What to check before buying a used Mercedes-Benz