Mercedes-Benz Cla MOT Failure Rate & Common Faults
We analysed 54,501 MOT tests on the Mercedes-Benz Cla carried out in 2023. 19% failed at the first attempt, which is well below the 29% average across all cars in the same data. Put another way, about 8 in 10 Clas passed first time.
Results cover cars first registered from 2013 to 2021. Compared with other cars of the same age, 2014 models did best (76% passed, +4.5 points against the average for 9-year-old cars), while 2020 models fared worst (86%, −2.1 points). Tested cars had covered 53,336 miles on average, against 73,145 across all cars.
The most common reason for failure was tyres, found on 9.1% of tests (slightly above the 6.3% seen across all cars). The single most frequent fault was "tread depth below requirements of 1.6mm", on 2.5% of tests.
- MOT tests analysed
- 54,501
- First-time pass rate
- 81%
- All cars: 71%
- Versus all cars
- +9.6 points
- Average mileage at test
- 53,336
- All cars: 73,145
Checking a particular Cla?
See its own MOT history, advisories and mileage for free.
Cla MOT pass rate by year
Older cars fail more often, so each year is compared with all cars of the same age. Bars above the dashed line did better than average for their age.
| First registered | Tests | Pass rate | All cars, same age | Difference | Avg mileage |
|---|---|---|---|---|---|
| 2021 | 399 | 91% | 91% | +0.6 points | 26,102 |
| 2020 | 7,579 | 86% | 88% | −2.1 points | 27,694 |
| 2019 | 8,423 | 84% | 86% | −1.8 points | 33,471 |
| 2018 | 8,434 | 83% | 84% | −1.5 points | 43,587 |
| 2017 | 8,313 | 81% | 82% | −0.5 points | 55,657 |
| 2016 | 7,799 | 79% | 79% | −0.0 points | 65,753 |
| 2015 | 6,950 | 78% | 75% | +2.3 points | 74,375 |
| 2014 | 4,439 | 76% | 72% | +4.5 points | 80,855 |
| 2013 | 2,155 | 71% | 68% | +2.7 points | 86,172 |
Why the Mercedes-Benz Cla fails its MOT
The share of tests with at least one failure in each area, compared with all cars.
| Failure area | Cla | All cars |
|---|---|---|
| Tyres | 9.1% | 6.3% |
| Brakes | 3.0% | 6.8% |
| Lights and electrics | 3.0% | 11.3% |
| Visibility | 3.0% | 4.8% |
| Suspension | 2.7% | 8.9% |
| Noise, emissions and leaks | 1.6% | 3.1% |
| Seatbelts and airbags | 1.1% | 1.0% |
| Road Wheels | 0.8% | 0.4% |
| Number plates and VIN | 0.5% | 0.4% |
| Body and structure | 0.4% | 3.5% |
Top 10 specific failure reasons
- 1tread depth below requirements of 1.6mm2.5%
- 2has ply or cords exposed2.5%
- 3has a cut in excess of the requirements deep enough to reach the ply or cords2.2%
- 4less than 1.5 mm thick1.7%
- 5fractured or broken1.6%
- 6inoperative or indicates a malfunction1.5%
- 7provides insufficient washer liquid1.4%
- 8has a bulge, caused by separation or partial failure of its structure1.1%
- 9warning lamp indicates a fault0.9%
- 10does not clear the windscreen effectively0.9%
Common Cla MOT advisories
Advisories don't cause a fail, but they show what's wearing out. On a used Cla, check whether these have been dealt with. Read our guide to MOT advisories.
| Advisory | Area | Share of tests |
|---|---|---|
| tread depth below requirements of 1.6mm | Tyres | 16.8% |
| less than 1.5 mm thick | Brakes | 8.5% |
| has a tear, caused by separation or partial failure of its structure | Tyres | 6.6% |
| in such a condition that it is seriously weakened | Brakes | 6.4% |
| significantly and obviously worn | Brakes | 3.3% |
| tread pattern not visible over the whole tread area when minimum depth required is 1.0mm | Tyres | 2.8% |
| has a cut in excess of the requirements deep enough to reach the ply or cords | Tyres | 2.7% |
| Child Seat fitted not allowing full inspection of adult belt | Non-component advisories | 2.1% |
| Nail in tyre | Non-component advisories | 2.0% |
| has a bulge, caused by separation or partial failure of its structure | Tyres | 1.4% |
Tips to help your Cla pass
Based on where Clas most often fail. For a full list, use our pre-MOT checklist.
Brakes · 3.0% of Cla tests
Don't ignore brake warning signs
Grinding, squealing, a soft pedal or the car pulling to one side under braking are all worth investigating before the MOT. Check whether the last test noted worn pads or discs; if so, they may now be below the limit.
Lights and electrics · 3.0% of Cla tests
Walk round every light
With a helper, check headlights on dipped and main beam, sidelights, brake lights, indicators, the rear fog light and the number plate lamp. Replace blown bulbs in pairs and make sure no lenses are cracked.
Visibility · 3.0% of Cla tests
Clear the view
Replace wiper blades that smear, fill the washer bottle and get chips in the windscreen repaired early, especially in the area directly in front of the driver.
Compare with other models
Is the Cla ULEZ compliant? See the Mercedes-Benz Cla ULEZ check, or view all Mercedes-Benz models.
Other Mercedes-Benz models
Models with similar pass rates
About this data
Based on 54,501 first MOT tests of the Mercedes-Benz Cla carried out in 2023.
Source: DVSA anonymised MOT test data (contains public sector information licensed under the Open Government Licence v3.0). First attempts on cars only; “pass rate” means passing first time. Averages cover all 32,735,164 cars tested (71% passed), and years with under 50 tests are hidden.
Learn more about how our data works.
Frequently asked questions
Answers from 54,501 first MOT tests of the Mercedes-Benz Cla.
What is the Mercedes-Benz Cla MOT failure rate?
In our data, 19% of 54,501 first MOT attempts on the Mercedes-Benz Cla ended in a fail, compared with 29% for all cars.
What is the most common reason a Mercedes-Benz Cla fails its MOT?
The most common failure areas were tyres (9.1% of tests), brakes (3.0% of tests), lights and electrics (3.0% of tests).
Which Cla year has the best MOT pass rate?
Allowing for age, 2014 cars performed best: 76% passed first time, +4.5 points against the average for 9-year-old cars. The weakest was 2020, at 86% (−2.1 points).
How many miles had a typical Mercedes-Benz Cla covered at its MOT?
The average was 53,336 miles, against 73,145 for all cars tested. 2021 cars averaged 26,102 miles and 2013 cars 86,172.
What is the most common MOT advisory on the Mercedes-Benz Cla?
"tread depth below requirements of 1.6mm" was recorded on 16.8% of tests, in the tyres area. 9.1% of Clas failed in that area too.
How can I check a specific Cla's MOT history?
Enter its registration in our free MOT check. Across the 54,501 Clas in our data, first-time pass rates ranged from 71% to 91% by year, so one car's own record says more than the average.
Related guides
- MOT · 4 min readTyre tread depth and the MOT: the legal limit and how to check6.3% of cars failed their 2023 MOT on tyres. The 1.6mm legal limit, what testers look for beyond tread, and a one-minute check with a 20p coin.Read the guide
- MOT · 6 min readDangerous, major and minor MOT defects explainedSince 2018, every fault found at an MOT goes into one of four categories. Knowing the difference tells you whether you can drive home, and what to fix first.Read the guide
- MOT · 6 min readPre-MOT checklist: 20 things to check yourself before the testTwenty quick checks, grouped by area, that you can do on your driveway in under half an hour. No tools beyond a coin and a helper needed for most.Read the guide
Check any Cla's MOT history
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