Used car guide

2021 BMW I3: common problems and what to check

What gets flagged at MOT on 2021 BMW I3s, from 3,503 tests in 2025, plus known faults and what to look at before you buy one.

3,503MOT tests in 2025
91%pass first time (all 2021 cars: 87%)
5,800typical miles a year
3.5×the usual rate for wheels

What stands out

Parts flagged at MOT more often on 2021 BMW I3s than on all cars registered in 2021.

  • Wheels3.5× usual
    BMW I3
    2.1% All 2021 cars
    0.6%

    Failed outright at MOT: 0.1%, against 0.2% of all 2021 cars. The rest were advisories or minor defects.

    Rough price £70–£150 our estimate

    At the viewing: Check the tread on all four tyres, including the inside edges, and look for cracks or bulges.

Better than most

Brake pads: 1.2% here, against 6.8% of all 2021 cars. Brake discs: 2.9% here, against 7.1% of all 2021 cars.

By area

The share of 2021 BMW I3 MOT tests where testers flagged each area, as a fail or an advisory. Rough prices are typical independent-garage costs.

  • Tyres
    27% of testsRough price £70–£150

    At the viewing: Check the tread on all four tyres, including the inside edges, and look for cracks or bulges.

  • Lights and electrics
    6% of testsRough price £10–£80

    At the viewing: Ask a friend to check every light, including brake lights and indicators, while you operate them.

  • Brakes
    4% of testsRough price £150–£350

    At the viewing: Look for a lip on the disc edges and feel for judder or pulling when braking firmly from about 40mph.

  • Wipers, windscreen and mirrors
    3% of testsRough price £15–£250

    At the viewing: Check for chips in the driver's view, and test the wipers and washers.

  • Seats and seatbelts
    2% of testsRough price £80–£250

    At the viewing: Pull each seatbelt sharply. It should lock, and retract cleanly.

  • Suspension
    1% of testsRough price £120–£400

    At the viewing: Listen for knocks over speed bumps, and look behind each front wheel for a snapped coil spring.

Looking at a BMW I3?

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Other years

YearMOT testsMost flagged
20222,911Tyres 24%
20204,111Tyres 29%
20194,050Tyres 30%
20183,108Tyres 28%
20173,170Tyres 30%
20162,157Tyres 32%
20151,890Tyres 31%
20141,171Tyres 34%

Where this comes from: the DVSA's anonymised results for every MOT test in Great Britain in 2025, counting tests of 2021 BMW I3s registered in 2021. "Flagged" includes advisories, so it isn't the same as a fail rate. How we score