KIA STONIC GT-LINE ISG MHEV (2021)
Running costs, common problems, and reliability data based on 1,620 real MOT tests in 2024.
MOT Pass Rate
96%
Total Tests (2024)
1,620
Avg Mileage
21,854 mi
Est. Annual Cost
£1,400
Is the 2021 KIA STONIC GT-LINE ISG MHEV reliable?
Excellent reliability. Very few MOT failures. That's 14 points above the national average of 82%. It also outperforms the KIA brand average of 86%.
At 3 years old, 96% of KIA STONIC GT-LINE ISG MHEVs from 2021 passed their MOT first time in 2024. That's based on 1,620 tests across the UK. The average mileage at this age is 21,854 miles.
How does the 2021 KIA STONIC GT-LINE ISG MHEV compare?
Mileage Analysis
The average 2021 KIA STONIC GT-LINE ISG MHEV has 21,854 miles on the clock, which is in line with the expected 22,200 miles for a 3-year-old car, suggesting normal everyday use.
Best year to buy a KIA STONIC GT-LINE ISG MHEV?
The most reliable year is the 2022 model with a 97% MOT pass rate, while the 2021 model has the lowest at 96%. Consider a different year if reliability is a priority.
How much does a 2021 KIA STONIC GT-LINE ISG MHEV cost to run?
Based on 7,400 miles/year (UK average), current fuel prices, and repair likelihood from MOT pass rate data. Insurance not included.
KIA STONIC GT-LINE ISG MHEV by Year
Checking a specific KIA STONIC GT-LINE ISG MHEV?
Enter the reg plate to see its individual MOT history, mileage verification, and predicted costs.
About the 2021 KIA STONIC GT-LINE ISG MHEV
The 2021 KIA STONIC GT-LINE ISG MHEV is a city car with a 998cc hybrid engine. 1,620 of these vehicles were MOT tested in 2024, making it a reasonably common sight on UK roads. It ranks in the top 15% of all 2021 cars for reliability.
With an average of 21,854 miles at 3 years old, KIA STONIC GT-LINE ISG MHEV owners drive about as much as the UK average.
2021 KIA STONIC GT-LINE ISG MHEV Fuel Costs
The modest 998cc hybrid 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 hybrid prices of 142p per litre (based on 7,400 miles per year). As a hybrid, real-world fuel costs will vary significantly depending on how much electric-only driving you do.
What does it cost to own a 2021 KIA STONIC GT-LINE ISG MHEV?
Total estimated annual running cost is £1,400 (£117/month), broken down as £955 fuel, £190 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
At 3 years old, this is still relatively fresh. You may find examples with remaining manufacturer warranty. Depreciation is slowing but hasn't bottomed out yet.
Alternatives to the 2021 KIA STONIC GT-LINE ISG MHEV
The KIA STONIC GT-LINE ISG MHEV is actually the most reliable option among similar hybrid city cars from this era. Here are comparable hybrid cars with similar engines:
- TOYOTA YARIS (2019) 93% pass rate (-3%) from 41,554 tests
- VOLVO XC40 (2021) 93% pass rate (-3%) from 25,698 tests
- HONDA JAZZ EX I-MMD CVT (2021) 96% pass rate (same) from 11,054 tests
- FORD PUMA TITANIUM MHEV (2021) 95% pass rate (-1%) from 7,555 tests