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MG 3 2018: MOT failure rate for its age

20.0% of 10,261 MOT tests of the MG 3 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 105.5 (95% CI 101.0–110.1; 100 = normal for this model at that age): the 2018 MG 3 fails more often than other build years of the same model at the same age.

MG 3 built in 2018 at a glance
MeasureValueUnitCompared withYearsTests
Failed first time20.0%all ages tested2019–202410261
Index against this model at the same age (95% CI 101.0–110.1)105.5index100 = normal for this model at that age2019–202410261
Rank among this model's 8 build years7of 81 = fails least for its age2019–202410261
Tested in 20242584testsmedian 33,291 miles20242584
line · MG 3 built 2018 · first-time MOT failure share by age · built 2018 16.8% vs model normal 15.1% at age 3 · 2019–2024
Built 2018 against MG 3 normal for the age: first-time MOT failure share at each age, age 3: 16.8% vs 15.1%; age 4: 18% vs 17.1%; age 5: 21.5% vs 20%; age 6: 23.6% vs 23.6%. Axis from 0% to 30%. DVSA MOT bulk data, 2019–2024.

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

How does the 2018 MG 3 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.

MG 3 built 2018: first-time MOT failure by age, against the model's normal rate at that age (2019–2024)
AgeTestsFailed, %95% intervalNormal for this model at that age, %Index (100 = normal)
32,54616.815.4–18.315.1111.4
42,5591816.6–19.617.1105.3
52,57221.520–23.220108
62,58423.622–25.323.699.9

Source: DVSA MOT bulk data · Window: 2019–2024 · n = 10,261 (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 MG 3?

The most common failure group on cars built in 2018 is tyres: 8.1 items per 100 first tests, against 8.3 across all build years of the MG 3. These counts are not age-adjusted: cars built in 2018 were tested at ages 3 to 6.

Failure items per 100 first tests, MG 3 built 2018 against the MG 3 in all build years (2019–2024, not age-adjusted)
Failure groupBuilt 2018, per 100All build years, per 100Items
Tyres8.18.3831
Brakes7.26.6738
Visibility4.45.7455
Lamps, reflectors and electrical equipment3.54.3356
Suspension2.94.9294

Source: DVSA MOT bulk data · Window: 2019–2024 · n = 10,307 (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 MG 3, 2018 ranks 7 (1 = fails least for its age). 2017: index 100.7. 2019: index 99.5.

MG 3 build years: index against the model at the same age (2019–2024)
Build yearIndex (100 = normal)95% intervalVerdictTests
201392.881.5–104.1no different (rough estimate)979
2014101.697.8–105.4no different9,938
2015100.997.6–104.2no different14,519
2016100.597.4–103.6no different18,604
2017100.797.1–104.3no different15,039
2018105.5101.0–110.1worse10,261
201999.595.0–104.0no different10,954
2020105.798.5–112.9no different4,946

Source: DVSA MOT bulk data · Window: 2019–2024 · n = 85,240 (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). MG 3 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/mg-3/2018/

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.

Other pages for this model

MG 3 2013 · MG 3 2014 · MG 3 2015 · MG 3 2016 · MG 3 2017 · MG 3 2019 · MG 3 2020 · MG 3 by postcode area · MG 3 body, chassis and structure failures · MG 3 brakes failures · MG 3 vehicle identification failures · MG 3 lamps, reflectors and electrics failures · MG 3 noise, emissions and leaks failures · MG 3 road wheels failures · MG 3 seat belts and airbags failures · MG 3 steering failures · MG 3 suspension failures · MG 3 tyres failures · MG 3 visibility failures