Mercedes-Benz CLA 2018: MOT failure rate for its age

16.3% of 34,292 MOT tests of the Mercedes-Benz CLA 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 103.7 (95% CI 101.0–106.4; 100 = normal for this model at that age): close to other build years of the same model at the same age (within 5 points of normal).

Mercedes-Benz CLA built in 2018 at a glance
Measure	Value	Unit	Compared with	Years	Tests
Failed first time	16.3	%	all ages tested	2019–2024	34292
Index against this model at the same age (95% CI 101.0–106.4)	103.7	index	100 = normal for this model at that age	2019–2024	34292
Rank among this model's 8 build years	6	of 8	1 = fails least for its age	2019–2024	34292
Tested in 2024	8362	tests	median 49,093 miles	2024	8362

Built 2018 against Mercedes-Benz CLA normal for the age: first-time MOT failure share at each age, age 3: 15.2% vs 14.1%; age 4: 14.4% vs 14.3%; age 5: 17.2% vs 16.2%; age 6: 18.4% vs 18.3%. Axis from 0% to 20%. DVSA MOT bulk data, 2019–2024.

Check a 2018 Mercedes-Benz CLA by registration · All Mercedes-Benz CLA 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 Mercedes-Benz CLA 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.

Mercedes-Benz CLA 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	8,880	15.2	14.5–16	14.1	108.1
4	8,612	14.4	13.6–15.1	14.3	100.5
5	8,438	17.2	16.4–18.1	16.2	106.3
6	8,362	18.4	17.5–19.2	18.3	100.3

Source: DVSA MOT bulk data · Window: 2019–2024 · n = 34,292 (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 Mercedes-Benz CLA?

The most common failure group on cars built in 2018 is tyres: 10.7 items per 100 first tests, against 11.4 across all build years of the Mercedes-Benz CLA. These counts are not age-adjusted: cars built in 2018 were tested at ages 3 to 6.

Failure items per 100 first tests, Mercedes-Benz CLA built 2018 against the Mercedes-Benz CLA in all build years (2019–2024, not age-adjusted)
Failure group	Built 2018, per 100	All build years, per 100	Items
Tyres	10.7	11.4	3,712
Visibility	5.5	5.5	1,906
Brakes	3.3	3.8	1,134
Lamps, reflectors and electrical equipment	1.9	2.6	648
Road Wheels	1.1	0.9	365

Source: DVSA MOT bulk data · Window: 2019–2024 · n = 34,651 (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 8 published build years of the Mercedes-Benz CLA, 2018 ranks 6 (1 = fails least for its age). 2017: index 99.2. 2019: index 104.7.

Mercedes-Benz CLA build years: index against the model at the same age (2019–2024)
Build year	Index (100 = normal)	95% interval	Verdict	Tests
2013	105.6	102.0–109.3	worse	13,200
2014	99.2	96.6–101.8	no different	26,731
2015	100.1	97.9–102.3	no different	42,068
2016	100.9	98.8–103.1	no different	47,234
2017	99.2	96.9–101.5	no different	44,185
2018	103.7	101.0–106.4	worse	34,292
2019	104.7	101.4–108.0	worse	25,371
2020	103.2	98.9–107.5	no different	15,129

Source: DVSA MOT bulk data · Window: 2019–2024 · n = 248,210 (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). Mercedes-Benz CLA 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/mercedes-cla/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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