MOT performance
Noise, emissions and leaks: MOT failure rates
3.2% of 65,477,892 MOT tests on cars and light vans in 2023–2024 failed on noise, emissions and leaks, 2,064,198 tests in all. Among models with at least 20,000 tests, rates relative to comparable cars range from -96% to +190%.
65,477,892 MOT tests on 34,140,187 vehicles, 2023–2024 · Source: DVSA (Open Government Licence) · Analysis: 73 Auto
Check a specific car's MOT history and running costsAt a glance
| Figure | Value | Basis |
|---|---|---|
| Tests failed on noise, emissions and leaks | 3.2% | 2,064,198 of 65,477,892 tests |
| Models compared | 320 | each with ≥ 20,000 tests |
Most common items
| Item | Area | Share of tests |
|---|---|---|
| Malfunction indicator lamp: inoperative or indicates a malfunction | Noise, emissions and leaks | 0.95% |
Failure items with their own page
- Malfunction indicator lamp: inoperative or indicates a malfunction · 0.95% of tests
- Catalyst emissions: Lambda reading after 2nd fast idle outside specified limits · 0.53% of tests
- Emissions not tested: unable to be completed · 0.27% of tests
- Catalyst emissions: carbon monoxide content after 2nd fast idle exceeds manufacturer's specified limits · 0.20% of tests
- Catalyst emissions: carbon monoxide content after 2nd fast idle exceeds default limits · 0.14% of tests
- Engine oil leaks: leaking excessively from engine · 0.13% of tests
- On or after 01/07/2008: emissions exceed manufacturer's specified limit · 0.12% of tests
- Catalyst emissions: emissions likely to be affected by an exhaust leak · 0.12% of tests
- Catalyst emissions: carbon monoxide content at idle exceeds manufacturer's specified limits · 0.10% of tests
- Pre 01/07/2008 Turbo: emissions exceed manufacturer's specified limit · 0.07% of tests
- Catalyst emissions: hydrocarbon content after 2nd fast idle exceeds manufacturer's specified limits · 0.07% of tests
- On or after 01/01/2014: emissions exceed manufacturer's specified limit · 0.06% of tests
- Catalyst emissions: carbon monoxide content at idle exceeds default limits · 0.06% of tests
- Catalyst emissions: hydrocarbon content after 2nd fast idle exceeds default limits · 0.06% of tests
Models that fail on it most often
Relative to cars of the same age, mileage and fuel.
| Model | Tests | Failed on it | vs similar cars |
|---|---|---|---|
| Peugeot 208 | 402,103 | 5.5% | +190% |
| BMW i3 | 43,497 | 0.3% | +140% |
| Vauxhall Antara | 43,032 | 6.4% | +137% |
| Jeep Renegade | 55,555 | 3.8% | +133% |
| MG ZS | 71,594 | 1.5% | +133% |
| Fiat Doblo | 95,744 | 6.9% | +125% |
| Smart Forfour | 48,547 | 4.2% | +112% |
| Peugeot RCZ | 22,156 | 6.1% | +101% |
| Rover Mini | 22,350 | 11.0% | +93% |
| Volkswagen Fox | 54,486 | 11.0% | +87% |
Models that fail on it least often
| Model | Tests | Failed on it | vs similar cars |
|---|---|---|---|
| Tesla Model S | 21,398 | 0.0% | -96% |
| Nissan Leaf | 81,819 | 0.0% | -91% |
| Lexus NX | 53,608 | 0.0% | -91% |
| Toyota C-HR | 153,637 | 0.0% | -85% |
| Lexus UX | 20,230 | 0.0% | -85% |
| BMW 640 | 20,209 | 0.4% | -80% |
| Suzuki Celerio | 55,281 | 0.3% | -79% |
| Renault Zoe | 37,670 | 0.0% | -75% |
| Volvo XC70 | 35,465 | 1.2% | -73% |
| BMW 4 Series | 206,848 | 0.5% | -72% |
Check the car you are looking at
Enter a UK registration to see that car's own MOT history and what it is likely to cost to own. Your first check is free and shows the vehicle summary and its headline ownership cost. The category-by-category breakdown is part of a paid check.
UK number plate or 17-character VIN
About this data. These are MOT test results, not a measure of mechanical reliability: a car's MOT outcome reflects its condition on the day, which depends on how it has been maintained and driven as well as how it was built. Figures cover class 4 vehicles (cars and light vans), normal tests only (retests excluded), outcomes pass, fail and pass after rectification at the station; vehicles at least 2.5 years old at test. Tests from 2023-01-01 to 2024-12-30. “Compared with similar cars” means compared with the national rate for cars of the same age, mileage band and fuel. Contains public sector information licensed under the Open Government Licence v3.0. Makes and models are matched to 73 Auto's vehicle catalogue; tests that can't be matched are left out rather than guessed. See how the MOT figures are produced.