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The cars that fail most on emissions
Which cars fail their MOT most on emissions?
Ranked by emissions defects recorded per MOT test, the Rover Metro records this area most often at 13.2%. A single test can record more than one defect, so this measures how prone a model is to emissions faults, not the share of tests failed overall.
| # | Model | Emissions defects per test | Emissions defects | Tests analysed |
|---|---|---|---|---|
| 1 | Rover Metro | 13.2% | 36,593 | 278,215 |
| 2 | Kia Pride | 12.8% | 9,573 | 75,055 |
| 3 | Mitsubishi Fto | 12.7% | 7,066 | 55,527 |
| 4 | Rover 220 | 12.0% | 30,956 | 258,088 |
| 5 | Alfa Romeo 146 | 11.7% | 4,153 | 35,546 |
| 6 | Alfa Romeo 145 | 11.5% | 3,328 | 29,035 |
| 7 | Daewoo Nexia | 11.3% | 9,011 | 79,431 |
| 8 | Renault 19 | 11.3% | 3,334 | 29,410 |
| 9 | Mitsubishi Ralliart | 11.1% | 2,648 | 23,859 |
| 10 | Vauxhall Calibra | 11.1% | 12,507 | 113,102 |
| 11 | Mazda Mx-6 | 11.0% | 3,167 | 28,825 |
| 12 | Renault 5 | 11.0% | 2,494 | 22,721 |
| 13 | Rover 214 | 10.9% | 112,873 | 1,034,354 |
| 14 | Citroen Saxo | 10.7% | 264,251 | 2,459,410 |
| 15 | Rover 216i | 10.6% | 6,561 | 62,181 |
| 16 | Rover MINI | 10.5% | 55,468 | 527,164 |
| 17 | Peugeot 106 | 10.5% | 301,883 | 2,883,213 |
| 18 | Ford Probe | 10.5% | 7,222 | 68,998 |
| 19 | Rover 414 | 10.4% | 39,355 | 376,706 |
| 20 | Audi 100 | 10.4% | 5,822 | 55,764 |
| 21 | Daihatsu Grand Move | 10.4% | 4,174 | 40,032 |
| 22 | Skoda Favorit | 10.3% | 5,654 | 54,842 |
| 23 | Renault R19 | 10.2% | 10,844 | 106,034 |
| 24 | Mitsubishi 3000 | 10.2% | 2,328 | 22,806 |
| 25 | Renault R21 | 10.2% | 2,372 | 23,367 |
| 26 | Austin MINI | 10.1% | 20,944 | 206,909 |
| 27 | Vauxhall Midi | 10.1% | 1,880 | 18,680 |
| 28 | Rover 111 | 10.0% | 14,920 | 148,739 |
| 29 | Rover 114 | 10.0% | 11,199 | 112,458 |
| 30 | Rover 420 | 9.9% | 36,547 | 369,483 |
| 31 | Austin Morris MINI | 9.8% | 4,359 | 44,380 |
| 32 | Citroen Ax | 9.8% | 34,387 | 350,263 |
| 33 | Austin Metro | 9.7% | 3,058 | 31,550 |
| 34 | Rover 416 | 9.6% | 62,292 | 648,529 |
| 35 | Mitsubishi Gto | 9.6% | 1,621 | 16,880 |
| 36 | Rover 820 | 9.4% | 8,747 | 92,758 |
| 37 | Audi 80 | 9.4% | 23,320 | 247,747 |
| 38 | Renault Safrane | 9.4% | 2,445 | 26,067 |
| 39 | Toyota Lite-Ace | 9.3% | 1,714 | 18,454 |
| 40 | Vauxhall Brava | 9.3% | 8,367 | 90,424 |
| 41 | Rover 200 | 9.3% | 5,969 | 64,526 |
| 42 | Audi Coupe | 9.2% | 5,563 | 60,326 |
| 43 | Suzuki Super | 9.2% | 3,545 | 38,535 |
| 44 | Volvo 300 | 9.2% | 5,581 | 60,785 |
| 45 | Volvo 400 | 9.2% | 29,595 | 322,542 |
| 46 | Rover 216 | 9.0% | 40,267 | 445,746 |
| 47 | Toyota Emina | 9.0% | 2,595 | 28,731 |
| 48 | Rover 100 | 9.0% | 13,921 | 154,644 |
| 49 | Daihatsu Hijet | 9.0% | 10,128 | 112,720 |
| 50 | Fiat Uno | 9.0% | 6,018 | 67,032 |
How this is worked out
Every figure is computed from the full DVSA MOT test and defect record, not a survey or a poll. Rates are the share of MOT tests that end in a failure (or a pass); area figures count that area's recorded defects against tests taken. A model is only ranked once it clears a minimum test count, so a single unlucky batch cannot distort a list. Motorcycles, which share the MOT dataset, are excluded so these are genuine car rankings. Age is the strongest driver of MOT failure, so older models and vans naturally rank higher. Figures describe how a model performs across the fleet; they are not a diagnosis of any individual car.
Data as of September 2026.
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Sources: DVSA MOT History API: MOT test results and defect data ยท DVSA MOT testing data for Great Britain