2018 Mazda 3 MOT pass rate: 86.1% (20,748 tests)
Is the 2018 3 getting worse?
Pass rate of 2018-registered cars across recent test years:
| Test year | Pass rate | |
|---|---|---|
| 2023 | 87.5% -0.6 vs same-age |
|
| 2024 | 85.5% -0.7 vs same-age |
|
| 2025 | 85.2% +0.4 vs same-age |
The raw rate normally falls as cars age. The “vs same-age” figure compares this cohort with all UK cars registered in the same year, so normal ageing is not mistaken for a bad model year.
What fails on a 2018 3
| # | System | Defects recorded | Share |
|---|---|---|---|
| 1 | Brakes | 1,488 | 31.6% |
| 2 | Tyres | 1,385 | 29.4% |
| 3 | Suspension | 907 | 19.2% |
| 4 | Visibility | 487 | 10.3% |
| 5 | Lamps, reflectors and electrical equipment | 251 | 5.3% |
| 6 | Road Wheels | 47 | 1.0% |
All 3 years compared
| Registration year | Tests | Pass rate | Vs same-age | Median mileage |
|---|---|---|---|---|
| 2004 | 2,257 | 58.6% | -5.7 pts | 96,388 |
| 2005 | 7,744 | 59.0% | -5.5 pts | 102,678 |
| 2006 | 11,162 | 60.6% | -3.8 pts | 103,732 |
| 2007 | 15,111 | 61.4% | -3.8 pts | 101,863 |
| 2008 | 18,261 | 60.4% | -4.7 pts | 97,981 |
| 2009 | 22,086 | 64.3% | -2.1 pts | 98,248 |
| 2010 | 24,373 | 66.7% | -0.7 pts | 96,826 |
| 2011 | 15,945 | 66.4% | -2.7 pts | 90,221 |
| 2012 | 14,586 | 72.1% | +0.9 pts | 86,556 |
| 2013 | 15,195 | 75.5% | +2.1 pts | 75,570 |
| 2014 | 24,835 | 74.7% | -1.1 pts | 72,514 |
| 2015 | 34,878 | 75.8% | -2.9 pts | 67,232 |
| 2016 | 31,393 | 77.2% | -4.1 pts | 58,044 |
| 2017 | 24,332 | 78.6% | -5.4 pts | 48,620 |
| 2018 (this page) | 20,748 | 86.1% | -0.3 pts | 39,441 |
| 2019 | 12,909 | 91.6% | +3.3 pts | 31,248 |
| 2020 | 12,210 | 92.5% | +2.6 pts | 25,514 |
| 2021 | 7,562 | 92.6% | +2.2 pts | 24,456 |
| 2022 | 2,398 | 94.9% | +3.6 pts | 22,732 |
Weighing up which year to buy? See the full ranking: Mazda 3 years to avoid.
- Free MOT history checkThe exact car’s failures, advisories and mileage trail — sellers can’t edit it
- Topdon OBD2 scannersTopdon diagnostic scanners with full-system readouts
- XTOOL diagnostic toolsXTOOL code readers for petrol and diesel cars
- Autel UK testersAutel professional-grade diagnostic testers
FAQs
Is a 2018 Mazda 3 reliable?
2018-registered examples passed 86.1% of their MOT tests (20,748 tests, 2023–2025), -0.3 points versus all UK cars registered in the same year. At roughly 8 years old with a median 39,441 miles, condition now varies car by car — always check the individual MOT history.
What mileage is too high for a 2018 3?
The median tested example shows 39,441 miles. Anything far beyond that isn't automatically bad — a motorway-mile car with consistent service records often beats a low-mileage school-run car — but price accordingly and scrutinise the mileage trail for gaps or drops.
Should I buy the petrol or diesel 2018 3?
In this cohort petrols pass 86.6% of tests against 80.6% for diesels. Mileage and use can explain part of that gap, so treat it as a reason to inspect DPF and emissions history, not a fuel-type verdict.
Source: DVSA Anonymised MOT tests and results, 2023–2025 extracts (96 million Class 4 initial tests; retests excluded). Only vehicles old enough for a routine first MOT are included. Age-adjusted figures compare the model-year cohort with all vehicles of the same registration year tested in the same calendar year. Contains public sector information licensed under OGL v3.0.