Kia

Kia Stonic GT Line S Isg MHEV (2021)

922 real MOT outcomes analysed • 95.4% first-time pass rate

2021 Kia Stonic GT Line S Isg MHEV

CarHunch analysed 922 real MOT records for the 2021 Kia Stonic GT Line S Isg MHEV. Real test outcomes — pass rates, defect profiles, mileage data — from verified DVLA records. Updated as new MOTs are recorded.
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AI Analysis Reliability Overview Check a Specific Reg Buyer's Checklist Pass Rate by Fuel Mileage Distribution MOT Averages Colour Breakdown Compare Models

This 2021 Kia Stonic GT-Line S is a genuinely reliable proposition: 95% of examples pass MOT first time, well above the UK average of 80%, and only 4.5% have ever picked up a dangerous defect. The hybrid powertrain delivers consistent results, with the vast majority of these vehicles running the Hybrid Electric variant and posting a 94.9% pass rate.

At a median mileage of 22,416 miles for a three-year-old car, these are relatively lightly driven examples, which explains why they're failing so rarely. When they do show issues, advisories outnumber failures by six to one (0.9 per vehicle versus 0.14), suggesting wear items rather than structural problems—if you're considering one, have the service history checked to confirm regular maintenance has kept up with its modest mileage.

The 2021 Kia Stonic GT Line S Isg MHEV passes its MOT first time more often than most UK vehicles (95.4% vs ~80% average) — and when it does fail, it's usually something minor and cheap to fix.

First-time pass
95.4%
UK average ~80%
Better than average
Dangerous (ever)
4.5%
At least once in MOT history
Check this vehicle
Avg failures / car
0.14
Over 2.2 tests on record
Low
Typical mileage
22k
Middle half: 16k–30k
For context
Good baseline reliability. A 95.4% first-time pass rate puts this well above the UK average — it's a well-sorted vehicle in this age bracket.

These stats describe 922 vehicles as a group. The specific vehicle you're looking at could be the one good example or the one outlier. Run its registration to find out.

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See this vehicle's full MOT history & AI hunches

Spot recurring advisories, hidden issues, and how it compares to 922 Kia Stonic GT Line S Isg MHEV cars.

UK

Before you buy a 2021 Kia Stonic GT Line S Isg MHEV

Based on MOT data from 922 vehicles — here's what to check.

  • 📋 Check the full MOT history. 4.5% of these vehicles have had a dangerous defect recorded - recurring advisories often signal problems years before they become failures.
    Search the reg on CarHunch for the full MOT history, reliability stats and a free AI-powered analysis of that exact vehicle.
  • 🔍 Brake pipes, sills and subframes are the key areas on a vehicle this age — structural rust is hard to spot without getting underneath. A mechanic will check all of this before you commit, and give you a concrete basis to negotiate on price. Inspection ClickMechanic
  • 📄 Outstanding finance, insurance write-offs and clocking won't appear in the MOT records — a dedicated history check covers all of this. Our link gets you 20% off automatically. History carVertical Get 20% off via CarHunch

Pass Rate by Fuel Type

Fuel type Vehicles Pass rate Avg failures
Hybrid Electric (Clean) (98%) 907 95.3% 0.15

Colour Breakdown

Based on 2,882 Kia Stonic GT Line S Isg MHEV vehicles registered in the UK — across all years. From DVLA registration records.

Grey 34.7%
999
Blue 29.2%
841
Red 14.8%
427
White 11%
317
Yellow 10.3%
298

Mileage Distribution

Most 2021 Kia Stonic GT Line S Isg MHEV vehicles sit in the blue band. If the vehicle you're looking at is outside it, it's either unusually low or high mileage for its age.

22,416
typical
15,776
low mileage
29,601
high mileage

Half of all 2021 Kia Stonic GT Line S Isg MHEV vehicles fall between 15,776 and 29,601 miles.

Is the mileage you're seeing normal?
Under 15,776 miles — lower than most. Could be great, or could be a vehicle that rarely moved. Check test frequency and mileage progression in the MOT history.
15,776–29,601 miles — normal for age. This is where most 2021 Kia Stonic GT Line S Isg MHEVs sit.
Over 39,961 miles — higher than typical. Not necessarily a problem, but check service history and look out for advisory build-up on tyres and brakes.

MOT History Averages

2.2
Avg MOT tests per vehicle
0.14
Avg failures per vehicle
0.9
Avg advisories per vehicle
Other model years — Kia Stonic GT Line S Isg MHEV: All Stonic GT Line S Isg MHEV years → Which year to buy? →
2022 2023

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