Does the Mercedes-Benz CLA fail the MOT on noise, emissions and leaks more than it should?
The Mercedes-Benz CLA records 1.31 noise, emissions and leaks failure items per 100 initial MOT tests (2019–2024), against 1.12 expected for a car of the same age mix: about as expected for its class and age (the difference is within its interval or under 0.5 items per 100 tests) (+0.19, 95% interval +0.14 to +0.23). It ranks 225 of 678 models on noise, emissions and leaks (1 = most failures above expected).
Data release dvsa-2024-v2 (24 Sep 2026) · page updated 30 Sep 2026 · all models on noise, emissions and leaks · check a Mercedes-Benz CLA by registration
What exactly fails on noise, emissions and leaks?
The most frequent DVSA defect wording in this group on the Mercedes-Benz CLA is “Engine MIL illuminated indicating a malfunction”, recorded 2,866 times in 2019–2024.
| DVSA defect wording | Items | Per 100 tests |
|---|---|---|
| Engine MIL illuminated indicating a malfunction | 2,866 | 1.10 |
| Lambda coefficient outside the default limits or the range specified by the manufacturer | 126 | 0.05 |
| Emissions levels exceed default limits | 98 | 0.04 |
| Emissions test unable to be completed | 86 | 0.03 |
| Emissions levels exceed the manufacturer's specified limits | 50 | 0.02 |
Source: DVSA MOT bulk data (OGL v3.0) · Window: 2019–2024 · n = 260,294 (initial tests) · Method: failure items (major and minor) grouped by DVSA's defect tree; wordings with 30+ items · Updated: 30 Sep 2026 · Release: dvsa-2024-v2 · CSV
If a Mercedes-Benz CLA gets a noise, emissions and leaks advisory, how often does it fail next time?
3.7% of Mercedes-Benz CLA MOTs with a noise, emissions and leaks advisory were followed by a fail in the same group at the next MOT, typically 12 months and 8,459 miles later (655 advisories followed).
Source: DVSA MOT bulk data (OGL v3.0) · Window: 2019–2024 · n = 655 (advisories followed) · Method: the same vehicles followed to their next ordinary MOT · Updated: 30 Sep 2026 · Release: dvsa-2024-v2 · CSV
Other pages for this model
Mercedes-Benz CLA 2013 · Mercedes-Benz CLA 2014 · Mercedes-Benz CLA 2015 · Mercedes-Benz CLA 2016 · Mercedes-Benz CLA 2017 · Mercedes-Benz CLA 2018 · Mercedes-Benz CLA 2019 · Mercedes-Benz CLA 2020 · Mercedes-Benz CLA in Norway · Mercedes-Benz CLA in Finland · Mercedes-Benz CLA in the Netherlands · Mercedes-Benz CLA by postcode area · Mercedes-Benz CLA body, chassis and structure failures · Mercedes-Benz CLA brakes failures · Mercedes-Benz CLA vehicle identification failures · Mercedes-Benz CLA lamps, reflectors and electrics failures · Mercedes-Benz CLA road wheels failures · Mercedes-Benz CLA seat belts and airbags failures · Mercedes-Benz CLA steering failures · Mercedes-Benz CLA suspension failures · Mercedes-Benz CLA tyres failures · Mercedes-Benz CLA visibility failures