MOT fail rates by first-use year
2018 SEAT Mii MOT fail rate and common faults
How SEAT Mii cars first used in 2018 did at their MOTs from 2022 to 2025, against all cars of the same age. From 5,094 DVSA MOT tests of these cars. First use is usually the date the car was first registered.
MOT data updated
At 7 years, tested in 2025
What stands out
- In 2025, at 7 years old, SEAT Mii cars first used in 2018 failed 17.3% of MOTs (1,280 tests), 3.3 points below the 20.6% for all cars that age.
- From 2022 to 2025, as these cars went from 4 to 7 years old, the fail rate moved from 14.3% to 17.3%.
- SEAT Mii cars first used a year earlier, in 2017, failed 19.9% at the same age of 7 years (1,495 tests, in 2024).
- The most common fail item that is not a wear item, for the SEAT Mii at 7 years, is suspension arm bush worn, at 1.2 per 100 MOTs (all cars: 0.6).
MOT fail rate by test year
| Test year | Age | MOT fail rate | Tests (n) | All cars | Difference |
|---|---|---|---|---|---|
| 2022 | 4 years | 14.3% | 1,269 | 13.4% | +1.0 pts |
| 2023 | 5 years | 14.9% | 1,266 | 15.3% | −0.4 pts |
| 2024 | 6 years | 15.5% | 1,279 | 17.8% | −2.3 pts |
| 2025 | 7 years | 17.3% | 1,280 | 20.6% | −3.3 pts |
Most common faults at 7 years
These figures cover all SEAT Mii MOTs at 7 years: cars first used 2015 to 2018, tested 2022 to 2025 (n=7,739). The list uses every first-use year so it has enough tests. Wear items (tyres, brake pads, wipers, bulbs) say more about upkeep than about the design.
MOT fail items
| Fail item | Per 100 MOTs | All cars |
|---|---|---|
| Side/position light not working Wear | 2.5 | 0.8 |
| Wipers not clearing screen Wear | 2.2 | 1.7 |
| Headlamp aim: too low Wear | 1.5 | 0.9 |
| Tyre tread below 1.6 mm Wear | 1.5 | 2.2 |
| Suspension arm bush worn | 1.2 | 0.6 |
| Fuel cap/sealing device: ineffective | 1.2 | 0.0 |
| Brake pads under 1.5 mm Wear | 1.2 | 2.0 |
| Service brake performance: excessively binding | 1.0 | 0.2 |
| Washers: provides insufficient washer liquid Wear | 1.0 | 1.0 |
| Tyre condition: has a cut in excess of the requirements deep enough to reach the ply or cords Wear | 1.0 | 1.3 |
Per 100 of the MOTs above (n=7,739). A test with two items counts once for each.
Advisories
| Advisory | Per 100 MOTs | All cars |
|---|---|---|
| Tyre condition: slightly damaged/cracking or perishing Wear | 14.8 | 8.9 |
| Tyre tread close to the legal limit or worn on the edge Wear | 11.8 | 15.0 |
| Brake discs: worn, pitted or scored, but not seriously weakened | 6.4 | 8.0 |
| Brake pads wearing thin Wear | 5.3 | 9.0 |
| Suspension pin or bush worn, without excessive movement | 4.3 | 3.0 |
| Brake discs: worn, but not excessively | 3.2 | 2.6 |
| Service brake performance: binding but not excessively | 1.7 | 0.6 |
| Non-component advisories: Nail in tyre | 1.5 | 2.0 |
| Tyre tread close to the legal limit, under the 1.0 mm rule Wear | 1.4 | 2.0 |
| Non-component advisories: Child Seat fitted not allowing full inspection of adult belt | 1.3 | 2.4 |
Per 100 of the MOTs above (n=7,739). A test with two items counts once for each.
Fuel type at 7 years
These figures cover all SEAT Mii MOTs at 7 years: cars first used 2015 to 2018, tested 2022 to 2025 (n=7,739). Each fuel is set against all cars of the same fuel and age. Fuels with fewer than 1,000 tests are not shown.
| Fuel | Share of tests | MOT fail rate | Tests (n) | All cars, same fuel | Median mileage |
|---|---|---|---|---|---|
| Petrol | 100.0% | 19.3% | 7,739 | 19.6% | 37,156 miles |
Fail rate by mileage at 7 years
These figures cover all SEAT Mii MOTs at 7 years: cars first used 2015 to 2018, tested 2022 to 2025 (n=7,739). At 7 years, SEAT Mii cars at 30,000 to 60,000 miles failed more often (19.9%, n=4,077) than those at under 30,000 miles (14.1%, n=2,608). Bands with fewer than 1,000 tests are not shown.
| Mileage at test | MOT fail rate | Tests (n) | All cars |
|---|---|---|---|
| Under 30,000 miles | 14.1% | 2,608 | 12.7% |
| 30,000 to 60,000 miles | 19.9% | 4,077 | 19.2% |
Car tax rules for a 2018 car
- Cars first registered from 1 April 2017 pay a first-year rate set by CO2 emissions, then the standard rate each year. A petrol, diesel or hybrid car with a list price over £40,000 also pays the expensive car supplement for five years, from the second tax payment.
These are the rules, not the amount for a specific car. Car tax check
ULEZ and clean air zones
- Petrol cars first registered from 2006 usually meet Euro 4, the petrol standard for the London ULEZ, so they usually do not pay the daily charge.
- The clean air zones in Birmingham and Bristol use the same Euro 4 petrol and Euro 6 diesel standards. The low emission zones in Scotland use them too, but enforce them with fines, not a daily charge.
The Euro standard of the car decides, not the year alone. ULEZ checker
Other years of the SEAT Mii
Other SEAT models first used in 2018
| Model | Age at test | MOT fail rate | Tests (n) | All cars |
|---|---|---|---|---|
| SEAT Leon (2018) | 7 years in 2025 | 21.4% | 21,027 | 20.6% |
| SEAT Ibiza (2018) | 7 years in 2025 | 27.6% | 13,012 | 20.6% |
| SEAT Arona (2018) | 7 years in 2025 | 23.5% | 12,098 | 20.6% |
| SEAT Ateca (2018) | 7 years in 2025 | 13.4% | 8,968 | 20.6% |
| SEAT Alhambra (2018) | 7 years in 2025 | 18.5% | 2,524 | 20.6% |
More on the SEAT Mii
Found one you might buy? Vet the specific car.
These figures describe 2018 SEAT Mii cars as a group, not any one car. The VetTheCar Buying Report looks at the car you are buying: its MOT history, what similar cars did next, and what to ask the seller.
Source
Contains public sector information licensed under the Open Government Licence v3.0. Source: DVSA anonymised MOT test data, class 4 normal MOT tests, 2022 to 2025. MOT data updated 28 September 2026.
Not affiliated with or endorsed by DVSA. How we calculate these figures · Data sources
Car tax and clean air zone rules are summarised from GOV.UK and Transport for London guidance. They are general rules and are not drawn from the MOT data.