2021 Kia Stonic Gt-Line Isg Mhev S-A — MOT failures & pass rate

Across 665 MOT tests analysed for the 2021 Kia Stonic Gt-Line Isg Mhev S-A, the most common recorded failure areas were visibility, tyres and lighting & signalling. Its pass rate of 94.7% was above the average for cars of a similar age (91.2%).

Pass rate

665

MOT tests analysed

5.3%

Fail rate

better than

vs cars of similar age

3.5

Avg age at test (yrs)

How it compares

Fail rate for this model-year against the segment and national averages for cars of a similar age.

Top failure categories

Most common MOT failure areas — 2021 Kia Stonic Gt-Line Isg Mhev S-A
#	Category	% of tests affected	Tests
1	Visibility	3.2%	21
2	Tyres	2.4%	16
3	Lighting & signalling	1.8%	12
4	Brakes	0.9%	6
5	Emissions & environmental	0.1%	1
6	Body, structure & corrosion	0.1%	1

Percentage of tests with at least one failure recorded in each category.

Most common specific failures

The exact components most often recorded as failures — more specific than the categories above.

Most frequently recorded failure items — 2021 Kia Stonic Gt-Line Isg Mhev S-A
#	Failure item	Times recorded
1	Wipers	17
2	Headlamp aim	13
3	Brake pads	9
4	Washers	6
5	Tread depth	3
6	Malfunction indicator lamp	1

Top advisory categories

Advisories aren't failures, but they flag work likely needed soon — useful when budgeting.

Most common MOT advisories — 2021 Kia Stonic Gt-Line Isg Mhev S-A
#	Category	% of tests with advisory	Tests
1	Tyres	12.0%	80
2	Brakes	7.4%	49
3	Other defects	5.6%	37
4	Visibility	3.6%	24
5	Steering	0.6%	4
6	Lighting & signalling	0.3%	2

Failure rate by mileage

Higher-mileage cars tend to fail more — often the most useful guide to real condition.

MOT fail rate by recorded mileage band.

Fail rate by recorded mileage — 2021 Stonic Gt-Line Isg Mhev S-A
Mileage band	Tests	Fail rate
0-30k	505	4.4%
30-60k	147	8.8%

Failure rate by age

How this model-year's MOT fail rate climbs as the cars get older.

Trend over time

Fail rate by dataset year — 2021 Stonic Gt-Line Isg Mhev S-A
Dataset year	Tests	Fail rate
2024	323	4.6%
2025	335	5.7%

What to check before buying a 2021 Stonic Gt-Line Isg Mhev S-A

Before buying a 2021 Kia Stonic Gt-Line Isg Mhev S-A, focus on the areas it most often fails on. Visibility accounted for 3.2% of tests for this year.

Visibility (3.2% of tests): Wipers, washers, mirrors and screen damage — usually inexpensive, but check for chips in the driver's line of sight. Typical repair: £15–£150.
Tyres (2.4% of tests): Usually a quick, known-cost fix, but check tread, age and uneven wear (which can hint at alignment or suspension issues). Typical repair: £50–£120 per tyre.
Lighting & signalling (1.8% of tests): Often a cheap bulb, but persistent issues can mean wiring or corrosion in the units. Typical repair: £10–£150.

Repair costs are rough UK ballpark ranges to set expectations, not quotes — actual prices vary widely by car, parts and garage.

Frequently asked questions

How many 2021 Kia Stonic Gt-Line Isg Mhev S-As pass their MOT?

94.7% of the 665 2021 Kia Stonic Gt-Line Isg Mhev S-A MOT tests in this dataset passed — a 5.3% fail rate.

What is the most common MOT failure on a 2021 Kia Stonic Gt-Line Isg Mhev S-A?

Visibility, recorded in 3.2% of tests, followed by tyres (2.4%).

Does the 2021 Stonic Gt-Line Isg Mhev S-A get worse with mileage?

Its MOT fail rate rises from 4.4% in the 0-30k band to 8.8% in the 30-60k band.

Methodology & source. Based on 665 MOT tests. Dataset: DVSA MOT testing data (2021,2022,2023,2024,2025). Data last updated 2026-07-01. Figures reflect MOT-testable defects only — read the methodology for how these are calculated and what they don't measure.