Does the Seat Mii fail the MOT on noise, emissions and leaks more than it should?
The Seat Mii records 2.31 noise, emissions and leaks failure items per 100 initial MOT tests (2019–2024), against 1.75 expected for a car of the same age mix: more than expected for its class and age (+0.56, 95% interval +0.46 to +0.65). It ranks 173 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 Seat Mii by registration
What exactly fails on noise, emissions and leaks?
The most frequent DVSA defect wording in this group on the Seat Mii is “Emissions levels exceed default limits”, recorded 815 times in 2019–2024.
| DVSA defect wording | Items | Per 100 tests |
|---|---|---|
| Emissions levels exceed default limits | 815 | 0.82 |
| Lambda coefficient outside the default limits or the range specified by the manufacturer | 593 | 0.60 |
| Emissions levels exceed the manufacturer's specified limits | 394 | 0.40 |
| Engine MIL illuminated indicating a malfunction | 248 | 0.25 |
| Emissions test unable to be completed | 140 | 0.14 |
Source: DVSA MOT bulk data (OGL v3.0) · Window: 2019–2024 · n = 99,179 (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
Other pages for this model
Seat Mii 2012 · Seat Mii 2013 · Seat Mii 2014 · Seat Mii 2015 · Seat Mii 2016 · Seat Mii 2017 · Seat Mii 2018 · Seat Mii 2019 · Seat Mii 2020 · Seat Mii in Norway · Seat Mii in Finland · Seat Mii in the Netherlands · Seat Mii by postcode area · Seat Mii body, chassis and structure failures · Seat Mii brakes failures · Seat Mii vehicle identification failures · Seat Mii lamps, reflectors and electrics failures · Seat Mii road wheels failures · Seat Mii seat belts and airbags failures · Seat Mii steering failures · Seat Mii suspension failures · Seat Mii tyres failures · Seat Mii visibility failures