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

11.8% of 2,448 MOT tests of the Mercedes-Benz GLS 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 101.0 (95% CI 89.4–112.6; 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. This is a rough estimate from a smaller sample.

Mercedes-Benz GLS built in 2018 at a glance
Measure	Value	Unit	Compared with	Years	Tests
Failed first time	11.8	%	all ages tested	2019–2024	2448
Index against this model at the same age (95% CI 89.4–112.6)	101.0	index	100 = normal for this model at that age	2019–2024	2448
Rank among this model's 5 build years	3	of 5	1 = fails least for its age	2019–2024	2448
Tested in 2024	580	tests	median 51,473 miles	2024	580

Built 2018 against Mercedes-Benz GLS normal for the age: first-time MOT failure share at each age, age 3: 10.7% vs 9.8%; age 4: 9.7% vs 11.7%; age 5: 12.8% vs 12.5%; age 6: 14.5% vs 13.1%. Axis from 0% to 20%. DVSA MOT bulk data, 2019–2024.

Check a 2018 Mercedes-Benz GLS by registration · All Mercedes-Benz GLS 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 GLS 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 GLS 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	647	10.7	8.5–13.3	9.8	108.3
4	628	9.7	7.6–12.3	11.7	83.3
5	593	12.8	10.4–15.7	12.5	102.2
6	580	14.5	11.9–17.6	13.1	110.9

Source: DVSA MOT bulk data · Window: 2019–2024 · n = 2,448 (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 GLS?

The most common failure group on cars built in 2018 is tyres: 11.1 items per 100 first tests, against 11.2 across all build years of the Mercedes-Benz GLS. 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 GLS built 2018 against the Mercedes-Benz GLS in all build years (2019–2024, not age-adjusted)
Failure group	Built 2018, per 100	All build years, per 100	Items
Tyres	11.1	11.2	274
Body, chassis, structure	4.6	2.7	114
Visibility	3.3	3.6	82
Brakes	3	2.5	73
Identification of the vehicle	1.3	1.1	31

Source: DVSA MOT bulk data · Window: 2019–2024 · n = 2,474 (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 5 published build years of the Mercedes-Benz GLS, 2018 ranks 3 (1 = fails least for its age). 2017: index 97.6. 2019: index 89.9.

Mercedes-Benz GLS build years: index against the model at the same age (2019–2024)
Build year	Index (100 = normal)	95% interval	Verdict	Tests
2016	108.1	96.7–119.6	no different (rough estimate)	2,569
2017	97.6	88.3–107.0	no different (rough estimate)	3,632
2018	101.0	89.4–112.6	no different (rough estimate)	2,448
2019	89.9	74.3–105.6	no different (rough estimate)	1,258
2020	122.0	98.8–145.2	no different (rough estimate)	817

Source: DVSA MOT bulk data · Window: 2019–2024 · n = 10,724 (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 GLS 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-gls/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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