KIA STONIC (2021)
Running costs, reliability data, and common problems from 250 real MOT tests.
Annual Cost
£1,405
£117/month
MOT Pass Rate
97%
Excellent
Road Tax
£195
Flat rate/year
Insurance
Grp 1-8
998cc Petrol
Great Choice
97% pass rate, £1405/year to run. 15 points above average.
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Annual Running Costs
~50 mpg
Flat rate (post-2017)
Low estimate due to excellent reliability
Based on 7,400 miles/year (UK average), current fuel prices, and repair likelihood from MOT data. Insurance not included.
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Reliability Verdict
Excellent reliability. Very few MOT failures. That's 15 points above the national average of 82%. It also outperforms the KIA brand average of 86%.
At 5 years old, 97% of KIA STONICs from 2021 passed their MOT first time in 2026. That's based on 250 tests across the UK. The average mileage at this age is 18,874 miles.
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How Does It Compare?
Mileage Analysis
18,874
Average miles
37,000
Expected for age
The average 2021 KIA STONIC has 18,874 miles on the clock, which is below the expected 37,000 miles for a 5-year-old car. This suggests lighter use than average, which generally means less wear on major components.
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KIA STONIC by Year
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About the 2021 KIA STONIC
The 2021 KIA STONIC is a city car with a 998cc petrol engine. 250 of these vehicles were MOT tested in 2026, making it a less common model in the UK market. It ranks in the top 10% of all 2021 cars for reliability.
With an average of 18,874 miles at 5 years old, KIA STONIC owners tend to use this car less than the typical driver.
2021 KIA STONIC Fuel Costs
The modest 998cc petrol engine keeps fuel costs low, which is a real advantage for a city car. Expect around 50 mpg in mixed driving, which works out to roughly £955 per year at current petrol prices of 142p per litre (based on 7,400 miles per year).
What does it cost to own a 2021 KIA STONIC?
Total estimated annual running cost is £1,405 (£117/month), broken down as £955 fuel, £195 road tax, £55 MOT, and £200 predicted repairs. The low repair estimate reflects the excellent 97% pass rate. These cars rarely fail their MOT, so unexpected bills are less likely.
KIA STONIC Reliability Trend
Newer KIA STONICs show better MOT pass rates than older ones, with an average improvement of 5 percentage points.
Buying a Used 2021 KIA STONIC
At 5 years old, the KIA STONIC 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
Based on the 2021 KIA STONIC's fuel type, age, and engine size, these are the most likely problem areas to check.
Coil Pack Failure
Medium riskSmaller petrol engines are prone to ignition coil failures, causing misfires and rough running. Replacement is £50-£150 per coil.
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 stacks up against similar cars for annual running costs, insurance, and tax.
| Car | Pass Rate | Fuel/yr | Tax/yr | Insurance | Total/yr |
|---|---|---|---|---|---|
| KIA STONIC(2021) | 97% | £955 | £195 | Grp 1-8 | £1405 |
| FORD FIESTA(2019) | 91% | £955 | £190 | Grp 1-8 | £1400-£5 |
| VOLKSWAGEN GOLF(2019) | 92% | £1137 | £190 | Grp 12-25 | £1582+£177 |
| VAUXHALL CORSA(2019) | 88% | £1137 | £190 | Grp 8-20 | £1732+£327 |
| AUDI A3(2019) | 92% | £955 | £190 | Grp 1-8 | £1400-£5 |
Estimates based on 7,400 miles/year, current fuel prices, and MOT data. Insurance groups are indicative. Actual costs vary by driver, location, and usage.
Related Kia Models
Explore other Kia cars or similar models in the same category.
KIA SPORTAGE
2016 · 1700cc Diesel
KIA PICANTO
2018 · 998cc Petrol
KIA CEED
2012 · 1591cc Diesel
FORD FIESTA
2019 · 998cc Petrol
VOLKSWAGEN GOLF
2019 · 1498cc Petrol
VAUXHALL CORSA
2019 · 1398cc Petrol
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