The SEAT Mii is a city car that shares its platform with the VW up! and Skoda Citigo. Discontinued in 2021, it was replaced in electric form only by the e-Mii electric. Simple and very affordable to run, it earned a strong reliability reputation. Popular with first-time drivers and urban commuters. The e-Mii electric (2019–2021) is a sought-after affordable used EV.
Quick Facts — SEAT Mii
Common Engines
1.0 MPI (60ps, 75ps), Electric (e-Mii)
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6 Most Common SEAT Mii Problems
These are the faults most frequently seen on the SEAT Mii by UK garages — ranked by how commonly they occur and what they cost to fix.
The 1.0 MPI petrol uses a timing belt — not a chain. Replacement is required every 4 years or 40,000 miles. This service is frequently missed on used examples. A snapped belt destroys the engine.
💷 Typical repair cost: £150–£400 (service) / £2,000+ (engine failure)
The air conditioning compressor can seize on older Mii models — a known issue across the up!/Mii/Citigo platform.
💷 Typical repair cost: £250–£600
The e-Mii has a 36.8 kWh battery. Real-world range on older examples can be lower than the quoted 162 miles WLTP. Check battery health before purchase.
💷 Typical repair cost: N/A — check before buying
Window regulator failures are occasionally seen on older Mii models.
💷 Typical repair cost: £80–£180
Rear wiper motor failures are seen on some Mii models.
💷 Typical repair cost: £60–£150
Individual door lock actuator failures on older Mii models.
💷 Typical repair cost: £60–£160
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SEAT Mii — MOT Tips
The timing belt on the 1.0 MPI must be in date — check the service history carefully. A missed timing belt is a critical risk and common MOT advisory. e-Mii EV high-voltage warnings must be clear. Check all wipers and door locks — both are MOT items.
Engine management light on before your MOT? It's an automatic fail. Run a
MotorLoom diagnostic for £1.99 to get the likely cause and repair cost before booking the test.
SEAT Mii Tyres
Most SEAT Mii models run 165/70 R14 or 175/65 R14 or 185/55 R15 depending on trim level and year. Always check the placard inside the driver's door for the exact size for your vehicle.
Summary
The Mii is one of the most reliable used city cars available. The timing belt service history is the single most important check on any petrol Mii. The e-Mii is a practical entry-level used EV but real-world range should be verified. Overall an excellent first car or urban runabout.
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