Kia Stonic GT-Line Isg MHEV S-A (2021)
Estimated running costs and MOT pass rates from 566 MOT tests in 2024.
Annual Cost
£1,630
£136/month
MOT Pass Rate
96%
Excellent
Road Tax
£200
Standard rate/year
Est. Insurance
Grp 1-8
998cc Hybrid
Great Choice
96% pass rate, £1,630/year to run. 14 points above average.
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Annual Running Costs
~50 mpg (petrol-engine estimate; hybrids usually use less)
Standard rate (from April 2017)
Low estimate due to excellent reliability
Estimates based on 7,400 miles/year (UK average), petrol at 174.57p a litre (GOV.UK weekly average, week of 19 October 2026), GOV.UK road tax rates and repair likelihood from MOT data. Insurance not included. Cars registered from April 2017 pay the £200 standard rate, plus £440 a year for five years (from the second year) if they cost over £40,000 new (over £50,000 for electric cars).
Reliability Verdict
Excellent reliability. Very few MOT failures. That's 14 points above the average of 82% across all models in our data. It also outperforms the Kia brand average of 86%.
96% of MOT tests on Kia Stonic GT-Line Isg MHEV S-As from 2021 ended in a pass in 2024, when they were about 3 years old. That's based on 566 tests across the UK, retests included. The average mileage recorded at those tests was 20,228 miles.
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How Does It Compare?
Mileage Analysis
20,228
Average miles
22,200
Expected for age
The average 2021 Kia Stonic GT-Line Isg MHEV S-A had 20,228 miles on the clock at its 2024 MOT, which is in line with the expected 22,200 miles for a 3-year-old car, suggesting normal everyday use.
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About the 2021 Kia Stonic GT-Line Isg MHEV S-A
The 2021 Kia Stonic GT-Line Isg MHEV S-A is a city car. Our records list a 998cc hybrid engine, though engines vary between versions. 566 MOT tests were recorded on this model in 2024, making it a less common model in the UK market. It ranks in the top 17% of all 2021 models for MOT pass rate.
With an average of 20,228 miles recorded at its 2024 MOT tests, Kia Stonic GT-Line Isg MHEV S-A owners drive about as much as the UK average.
2021 Kia Stonic GT-Line Isg MHEV S-A Fuel Costs
The modest 998cc hybrid engine keeps fuel costs low, which is a real advantage for a city car. Our estimate uses around 50 mpg, the figure for a petrol engine of this size, which works out to roughly £1,175 per year with petrol at 174.57p per litre (GOV.UK weekly average, week of 19 October 2026; based on 7,400 miles per year). As a hybrid it should use less than that, and real-world fuel costs depend a lot on how much electric-only driving you do.
What does it cost to own a 2021 Kia Stonic GT-Line Isg MHEV S-A?
Total estimated annual running cost is £1,630 (£136/month), broken down as £1,175 fuel, £200 road tax, £55 MOT, and £200 predicted repairs. The low repair estimate reflects the excellent 96% pass rate. These cars rarely fail their MOT, so unexpected bills are less likely.
Buying a Used 2021 Kia Stonic GT-Line Isg MHEV S-A
At 5 years old, the Kia Stonic GT-Line Isg MHEV S-A offers good value with plenty of life remaining. Most manufacturer warranties will have expired, so a pre-purchase inspection is worth the cost.
Common Issues to Watch For
These are typical issues for cars of this age, fuel type and engine size, not faults recorded on this model's MOT tests. Use them as a checklist when you view one.
Hybrid Battery Health
Medium riskAfter 5 years, hybrid battery capacity may have reduced. A full replacement costs £2,000-£4,000, though reconditioning is cheaper at £500-£1,500.
Inverter and Power Electronics
Low riskThe inverter converts DC to AC for the electric motor. Failures are expensive (£1,500+) but relatively rare. Listen for unusual buzzing sounds.
Regenerative Braking
Medium riskBrake discs can corrode from reduced use (the electric motor handles most braking). Surface rust is normal but deep pitting needs attention.
Service History
Low riskAlways request a full service history. Regular servicing is the single best indicator of how well a car has been maintained, regardless of mileage.
Running Costs Compared
How the 2021 Kia Stonic GT-Line Isg MHEV S-A stacks up against similar cars for estimated annual running costs, insurance group, and tax.
| Car | Pass Rate | Fuel/yr | Tax/yr | Est. Ins. Group | Total/yr |
|---|---|---|---|---|---|
| Kia Stonic GT-Line Isg MHEV S-A(2021) | 96% | £1,175 | £200 | Grp 1-8 | £1,630 |
| Toyota Yaris(2019) | 93% | £1,398 | £200 | Grp 12-25 | £1,853+£223 |
| Volvo XC40(2021) | 93% | £1,398 | £200 | Grp 12-25 | £1,853+£223 |
| Toyota Yaris Design HEV CVT(2021) | 96% | £1,398 | £200 | Grp 12-25 | £1,853+£223 |
| Honda Jazz Ex I-MMD CVT(2021) | 96% | £1,398 | £200 | Grp 12-25 | £1,853+£223 |
Estimates based on 7,400 miles/year, GOV.UK average pump prices for the week of 19 October 2026, GOV.UK road tax rates and MOT data. Insurance groups are our rough estimate from engine size, not official groups. Actual costs vary by driver, location, and usage.
Questions about the 2021 Kia Stonic GT-Line Isg MHEV S-A
Is the 2021 Kia Stonic GT-Line Isg MHEV S-A reliable?
Excellent reliability. Very few MOT failures. 96% of MOT tests on 2021 Kia Stonic GT-Line Isg MHEV S-As ended in a pass, from 566 tests (DVSA MOT data for tests in 2024, retests included). That's 14 points above the average of 82% across all models in the same data.
How much does a 2021 Kia Stonic GT-Line Isg MHEV S-A cost to run?
Our estimate is £1,630 a year (£136 a month): £1,175 fuel, £200 road tax, £55 MOT and £200 predicted repairs, based on 7,400 miles a year. Insurance is not included.
What is the MOT pass rate for a 2021 Kia Stonic GT-Line Isg MHEV S-A?
96% of 566 MOT tests on the 2021 Kia Stonic GT-Line Isg MHEV S-A ended in a pass (DVSA MOT data for tests in 2024, retests included). That ranks it 538th of 3,336 models first registered in 2021 (top 17%).
What is the average mileage for a 2021 Kia Stonic GT-Line Isg MHEV S-A?
The average mileage recorded at MOT tests on the 2021 Kia Stonic GT-Line Isg MHEV S-A is 20,228 miles, which is in line with the expected 22,200 miles for a 3-year-old car, suggesting normal everyday use.
Related Kia Models
Explore other Kia cars or similar models in the same category.
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2018 · 998cc Petrol
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Toyota Yaris
2019 · 1497cc Hybrid
Volvo XC40
2021 · 1470cc Hybrid
Toyota Yaris Design HEV CVT
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