Kia Stonic 2018: MOT failure rate for its age

11.4% of 27,536 MOT tests of the Kia Stonic first registered in 2018 failed at the first attempt (2019–2024; retests excluded). Against this model's own normal rate at the same ages the index is 102.5 (95% CI 98.9–106.1; 100 = normal for this model at that age): the 2018 build year is no different from other years of the same model at the same age.

Kia Stonic built in 2018 at a glance
Measure	Value	Unit	Compared with	Years	Tests
Failed first time	11.4	%	all ages tested	2019–2024	27536
Index against this model at the same age (95% CI 98.9–106.1)	102.5	index	100 = normal for this model at that age	2019–2024	27536
Rank among this model's 4 build years	3	of 4	1 = fails least for its age	2019–2024	27536
Tested in 2024	6843	tests	median 40,266 miles	2024	6843

Built 2018 against Kia Stonic normal for the age: first-time MOT failure share at each age, age 3: 6.8% vs 7.3%; age 4: 11.4% vs 10.4%; age 5: 13.2% vs 13%; age 6: 14.3% vs 13.9%. Axis from 0% to 20%. DVSA MOT bulk data, 2019–2024.

Check a 2018 Kia Stonic by registration · All Kia Stonic MOT statistics · Download the build-year table (CSV)

Data release dvsa-2024-v2 (24 Sep 2026) · page updated 30 Sep 2026 · full dataset (v5).

How does the 2018 Kia Stonic fail at each age?

Cars built in 2018 were tested at ages 3 to 6 between 2019 and 2024. Each row compares their first-time failure share with what this model normally shows at that age, after allowing for the overall failure level of each test year.

Kia Stonic built 2018: first-time MOT failure by age, against the model's normal rate at that age (2019–2024)
Age	Tests	Failed, %	95% interval	Normal for this model at that age, %	Index (100 = normal)
3	6,946	6.8	6.3–7.5	7.3	93.5
4	6,881	11.4	10.7–12.2	10.4	109.3
5	6,866	13.2	12.4–14	13	101.6
6	6,843	14.3	13.5–15.1	13.9	102.9

Source: DVSA MOT bulk data · Window: 2019–2024 · n = 27,536 (initial tests) · Method: normal rate = this model's first-time failure share at that age across its build years (cells of 400+ tests), adjusted for each test year's overall level; cells of 30+ tests, under 500 marked rough · Updated: 30 Sep 2026 · Release: dvsa-2024-v2 · CSV

What fails most on the 2018 Kia Stonic?

The most common failure group on cars built in 2018 is visibility: 5.8 items per 100 first tests, against 5.8 across all build years of the Kia Stonic. These counts are not age-adjusted: cars built in 2018 were tested at ages 3 to 6.

Failure items per 100 first tests, Kia Stonic built 2018 against the Kia Stonic in all build years (2019–2024, not age-adjusted)
Failure group	Built 2018, per 100	All build years, per 100	Items
Visibility	5.8	5.8	1,620
Brakes	3.9	3.3	1,076
Tyres	3.3	2.8	905
Lamps, reflectors and electrical equipment	1.6	1.4	453
Suspension	0.5	0.5	150

Source: DVSA MOT bulk data · Window: 2019–2024 · n = 27,715 (initial tests of this build year) · Method: failure items grouped by DVSA's top-level defect groups, per 100 initial tests; groups with 30+ items · Updated: 30 Sep 2026 · Release: dvsa-2024-v2 · CSV

How does 2018 compare with the years around it?

Among the 4 published build years of the Kia Stonic, 2018 ranks 3 (1 = fails least for its age). 2017: index 90.2. 2019: index 102.3.

Kia Stonic build years: index against the model at the same age (2019–2024)
Build year	Index (100 = normal)	95% interval	Verdict	Tests
2017	90.2	81.2–99.2	better (rough estimate)	3,561
2018	102.5	98.9–106.1	no different	27,536
2019	102.3	98.3–106.3	no different	24,606
2020	107.7	100.5–114.9	worse	9,179

Source: DVSA MOT bulk data · Window: 2019–2024 · n = 64,882 (initial tests) · Method: observed failures against those expected for the same model at the same ages, test-year level adjusted; verdict follows the printed one-decimal bound · Updated: 30 Sep 2026 · Release: dvsa-2024-v2 · CSV

How to cite this page

MOT Risk Index (2026). Kia Stonic 2018 MOT statistics (data release dvsa-2024-v2; full dataset motriskindex-families-2024-v5, DOI 10.5281/zenodo.22975051), updated 30 September 2026. motriskindex.co.uk/cars/kia-stonic/2018/

How every figure is calculated: methodology. Age, test year and build year are tied together (age = test year − build year), so the test-year level is taken as observed, not estimated.

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