Used car guide

2016 Kia Optima diesel: common problems and MOT failures

What MOT testers find on the diesel Kia Optima first registered in 2016 (diesel cars only): we looked at the 2,963 MOTs these cars had during 2023–2025. Plus known faults and what to look at before you buy one.

2,963MOTs of 2016 diesel cars, done in 2023–2025
81%pass first time (all 2016 cars: 77%)
9,400typical miles a year
2.3×the usual rate for number plates

What goes wrong more than usual on a 2016 Kia Optima diesel?

Parts flagged at MOT more often on the 2016 Kia Optima diesel than on all cars registered in 2016.

  • Number plates2.3× usual
    Kia Optima
    3.9% All 2016 cars
    1.7%

    Failed outright at MOT: 0.1%, against 0.2% of all 2016 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.

  • Braking performance1.8× usual
    Kia Optima
    4.1% All 2016 cars
    2.3%

    Failed outright at MOT: 1%, against 0.8% of all 2016 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.

Better than most

Suspension arm bushes and joints: 0.7% here, against 4.9% of all 2016 cars.

Common 2016 Kia Optima diesel MOT failures and advisories

The share of 2016 Kia Optima diesel MOT tests where testers flagged each area, as a fail or an advisory. Rough prices are typical independent-garage costs.

  • Tyres
    31% 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
    29% 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.

  • Suspension
    8% 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.

  • 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.

  • Wipers, windscreen and mirrors
    5% of testsRough price £15–£250

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

  • Exhaust and emissions
    3% of testsRough price £100–£1,200

    At the viewing: Look for black soot in the tailpipe, listen for blowing from the exhaust and check for engine or DPF warning lights.

Questions to ask the seller before buying a 2016 Kia Optima diesel

Ask before you travel to see it. A seller who knows the car will have answers, and receipts.

  1. Any recent work on the number plates? (Flagged at MOT 2.3× as often on the 2016 Kia Optima diesel as on other cars the same age.)
  2. Any recent work on the braking performance? (Flagged at MOT 1.8× as often on the 2016 Kia Optima diesel as on other cars the same age.)
  3. Can I see the service history and receipts for any big jobs?

Looking at a Kia Optima?

Check the actual car: its own MOT history, mileage and what to ask the seller. Free, no sign-up.

Other years

Every year of the Kia Optima compared

YearMOT testsMost flagged
2020420Tyres 29%
20195,021Tyres 30%
20187,986Tyres 31%
20179,790Tyres 32%
20151,807Tyres 31%
20141,735Tyres 33%
2013971Brakes 38%
20121,919Brakes 43%
2011–Too few tests

Where this comes from: the DVSA's anonymised results for every MOT test done in Great Britain during 2023–2025, counting the MOTs of Kia Optima cars first registered in 2016. "Flagged" includes advisories, so it isn't the same as a fail rate. How we score