Smart Forfour 2015: MOT failure rate for its age
25.4% of 33,221 MOT tests of the Smart Forfour first registered in 2015 failed at the first attempt (2019–2024; retests excluded). Against this model's own normal rate at the same ages the index is 105.6 (95% CI 103.3–107.9; 100 = normal for this model at that age): the 2015 Smart Forfour fails more often than other build years of the same model at the same age.
| Measure | Value | Unit | Compared with | Years | Tests |
|---|---|---|---|---|---|
| Failed first time | 25.4 | % | all ages tested | 2019–2024 | 33221 |
| Index against this model at the same age (95% CI 103.3–107.9) | 105.6 | index | 100 = normal for this model at that age | 2019–2024 | 33221 |
| Rank among this model's 9 build years | 9 | of 9 | 1 = fails least for its age | 2019–2024 | 33221 |
| Tested in 2024 | 5490 | tests | median 48,415 miles | 2024 | 5490 |
Data release dvsa-2024-v2 (24 Sep 2026) · page updated 30 Sep 2026 · full dataset (v5).
How does the 2015 Smart Forfour fail at each age?
Cars built in 2015 were tested at ages 4 to 9 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.
| Age | Tests | Failed, % | 95% interval | Normal for this model at that age, % | Index (100 = normal) |
|---|---|---|---|---|---|
| 4 | 5,699 | 20.3 | 19.3–21.4 | 19.8 | 102.6 |
| 5 | 5,382 | 21.4 | 20.3–22.5 | 19.4 | 110.2 |
| 6 | 5,528 | 22.6 | 21.5–23.7 | 21.4 | 105.4 |
| 7 | 5,573 | 26 | 24.9–27.2 | 24.2 | 107.6 |
| 8 | 5,549 | 29.6 | 28.5–30.9 | 28.1 | 105.4 |
| 9 | 5,490 | 32.4 | 31.2–33.6 | 31.3 | 103.5 |
Source: DVSA MOT bulk data · Window: 2019–2024 · n = 33,221 (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 2015 Smart Forfour?
The most common failure group on cars built in 2015 is tyres: 10.4 items per 100 first tests, against 9.1 across all build years of the Smart Forfour. These counts are not age-adjusted: cars built in 2015 were tested at ages 4 to 9.
| Failure group | Built 2015, per 100 | All build years, per 100 | Items |
|---|---|---|---|
| Tyres | 10.4 | 9.1 | 3,471 |
| Visibility | 8.5 | 8.9 | 2,840 |
| Suspension | 7.2 | 7.5 | 2,380 |
| Lamps, reflectors and electrical equipment | 6.1 | 14.2 | 2,011 |
| Brakes | 4.7 | 7.1 | 1,574 |
Source: DVSA MOT bulk data · Window: 2019–2024 · n = 33,221 (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 2015 compare with the years around it?
Among the 9 published build years of the Smart Forfour, 2015 ranks 9 (1 = fails least for its age). 2007: index 95.2. 2016: index 102.7.
| Build year | Index (100 = normal) | 95% interval | Verdict | Tests |
|---|---|---|---|---|
| 2004 | 103.3 | 98.4–108.3 | no different (rough estimate) | 3,594 |
| 2005 | 99.2 | 96.3–102.1 | no different | 10,374 |
| 2006 | 96.7 | 93.6–99.7 | better | 8,887 |
| 2007 | 95.2 | 84.2–106.2 | no different (rough estimate) | 702 |
| 2015 | 105.6 | 103.3–107.9 | worse | 33,221 |
| 2016 | 102.7 | 100.2–105.1 | worse | 31,503 |
| 2017 | 98.2 | 95.3–101.0 | no different | 25,286 |
| 2018 | 94.4 | 90.7–98.1 | better | 15,417 |
| 2019 | 92.3 | 86.2–98.4 | better | 5,911 |
Source: DVSA MOT bulk data · Window: 2019–2024 · n = 134,895 (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). Smart Forfour 2015 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/smart-forfour/2015/
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
Smart Forfour 2004 · Smart Forfour 2005 · Smart Forfour 2006 · Smart Forfour 2007 · Smart Forfour 2016 · Smart Forfour 2017 · Smart Forfour 2018 · Smart Forfour 2019 · Smart Forfour in Finland · Smart Forfour in the Netherlands · Smart Forfour by postcode area · Smart Forfour body, chassis and structure failures · Smart Forfour brakes failures · Smart Forfour vehicle identification failures · Smart Forfour lamps, reflectors and electrics failures · Smart Forfour noise, emissions and leaks failures · Smart Forfour road wheels failures · Smart Forfour seat belts and airbags failures · Smart Forfour steering failures · Smart Forfour suspension failures · Smart Forfour tyres failures · Smart Forfour visibility failures