Kia Rio 2018: reliability & common MOT faults
Elevated MOT failure patterns for the 2018 Kia Rio include Daytime running lamps (front) (~5.1× peers) and Ball joint dust cover (front) (~2.9× peers). Based on UK DVSA open data for test year 2025 (853 failed first-attempt tests), compared with similar age and mileage peers. Available test years: 2024, 2025.
Common faults
These are MOT failure patterns that show up more often on this registration year than on similar cars of the same class, age band, and mileage in the same test year (leave-one-out peer comparison; whole model family excluded).
Statistical patterns from MOT defect codes — not manufacturer TSBs, recalls, or a diagnosis of any individual car. Fail and advisory patterns are kept separate.
Based on 853 failed first-attempt tests in test year 2025.
Daytime running lamps (front)
This failure pattern appears about 5.1× more often than on similar peer cars — recorded on 30 failed first-attempt tests; 3.5% of failed tests for this model year.
Front · 30 failures · ×5.1 vs similar cars · 3.5% of failed first tests · Likely common fault pattern
Ball joint dust cover (front)
This failure pattern appears about 2.9× more often than on similar peer cars — recorded on 29 failed first-attempt tests; 3.4% of failed tests for this model year.
Front · 29 failures · ×2.9 vs similar cars · 3.4% of failed first tests · Possible elevated fault
No patterns met the strongest callout thresholds on this page; showing the highest-lift rows that still cleared the display floors.
| # | Fault pattern | Location | Failures | vs similar cars | Share of fails | Confidence |
|---|---|---|---|---|---|---|
| 1 |
Daytime running lamps (front)
Lamps, reflectors and electrical equipment > Daytime running lamps
|
Front | 30 | ×5.1 | 3.5% | Likely common fault pattern |
| 2 |
Ball joint dust cover (front)
Suspension > Suspension arms > Ball joint dust cover
|
Front | 29 | ×2.9 | 3.4% | Possible elevated fault |
Only patterns that clear minimum sample and elevation thresholds are shown (at least 20 failures and 2.0× peer lift).
Advisories
Advisory items recorded on failed first-attempt tests that appear elevated versus peers. Advisories are not a fail rate — they flag issues noted at the test, often before they become failures.
| # | Advisory pattern | Location | Notes | vs similar cars | Share | Confidence |
|---|---|---|---|---|---|---|
| 1 |
Non-component advisories (front)
Non-component advisories
|
Front | 31 | ×2.5 | 3.6% | Elevated vs peers |
FAQs
About this data
Universe. UK class 4 cars only; normal MOT tests (not retests); results pass, PRS, or fail; one first test per vehicle per calendar year.
PRS policy. PRS means the vehicle failed items that were fixed at the test station and then passed the same day. We count PRS as a first-attempt fail in headline rates so same-day repairs do not hide problems.
Peer baseline. We compare this model year with other class 4 cars of similar age and mileage in the same test year, excluding the whole model family so the car is not compared with itself (leave-one-out peer baseline).
Data years. Test years covered: 2024, 2025.
Limitations.
- MOT tests do not cover engine internals, gearboxes, or many electronic modules — so this is not a full reliability score.
- Common faults are inferred from MOT defect statistics, not manufacturer TSBs or recalls.
- Matching on age and mileage reduces but does not remove every usage or maintenance difference between cars.
- Pass rates and star scores appear only when those data marts are available; this page never invents them.
Display rules config: 1
Contains public sector information licensed under the Open Government Licence v3.0.