Used car guide

2018 Hyundai Ioniq: common problems and what to check

What gets flagged at MOT on 2018 Hyundai Ioniqs, from 8,718 tests in 2025, plus known faults and what to look at before you buy one.

8,718MOT tests in 2025
85%pass first time (all 2018 cars: 81%)
11,900typical miles a year
2.6×the usual rate for braking performance

What stands out

Parts flagged at MOT more often on 2018 Hyundai Ioniqs than on all cars registered in 2018.

  • Braking performance2.6× usual
    Hyundai Ioniq
    3.7% All 2018 cars
    1.4%

    Failed outright at MOT: 1.6%, against 0.5% of all 2018 cars. The rest were advisories or minor defects.

    Rough price £100–£350 our estimate

    At the viewing: On a quiet road, brake firmly from about 30mph. The car should stop straight without pulling.

  • Number plate lights1.9× usual
    Hyundai Ioniq
    3.4% All 2018 cars
    1.8%

    Failed outright at MOT: 1.5%, against 0.6% of all 2018 cars. The rest were advisories or minor defects.

    Rough price £5–£40 our estimate

    At the viewing: Check the number plate lights work and the plates are clean and legal.

Better than most

Brake pads: 4.3% here, against 11% of all 2018 cars.

By area

The share of 2018 Hyundai Ioniq MOT tests where testers flagged each area, as a fail or an advisory. Rough prices are typical independent-garage costs.

  • Tyres
    23% 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.

  • Brakes
    15% 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.

  • Lights and electrics
    8% of testsRough price £10–£80

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

  • Wipers, windscreen and mirrors
    4% of testsRough price £15–£250

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

  • Suspension
    4% 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.

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

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

Looking at a Hyundai Ioniq?

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Other years

YearMOT testsMost flagged
202210,667Tyres 21%
202112,567Tyres 23%
20207,715Tyres 25%
20199,698Tyres 23%
20175,668Tyres 23%

Where this comes from: the DVSA's anonymised results for every MOT test in Great Britain in 2025, counting tests of 2018 Hyundai Ioniqs registered in 2018. "Flagged" includes advisories, so it isn't the same as a fail rate. How we score