Kia Rio Mk4 (YB) (2017-present) reliability
Kia Rio Mk4 (YB) built around 2018: about average at the MOT
Kia Rio Mk4 (YB) models built around 2018 fail their MOT about as often as similar cars the same age.
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Key figure
14% of MOT tests on Kia Rio Mk4 (YB) models built around 2018 ended in a fail (retests included), against 14% for similar cars the same age.
Most common issue
The most common MOT issue on Kia Rio Mk4 (YB) models built around 2018 involves the tyres.
Based on 33,192 tests of Rio models registered 2017+.
About 1 in 10 petrol Rio cars registered in 2022 (9.5%) failed their first MOT.
Based on 2,904 first MOTs (DVSA MOT results, 2025).
About 1 in 75 Rio Mk4 (YB) MOTs (1.5%) failed and still hadn't passed 3 days later. That's for cars built around 2018 (7 years old), all fuels combined.
Based on 7,421 tests (DVSA MOT results, 2025). A fail that passed a retest within 3 days, even the same day, isn't counted. Nor is a fail with no later MOT on record.
About 1 in 20 Rio Mk4 (YB) MOTs (4.6%) found at least one dangerous defect. These are cars built around 2018 (7 years old).
Based on 7,421 tests (DVSA MOT results, 2025). Dangerous is the most serious grade an MOT gives: a direct risk to road safety.
Mk4 (YB) fail rate by age
Fail rate is the share of MOT tests that ended in a fail. Retests count as tests. How we count fail rates Build years are worked out from age, so they are approximate. Tests counted are 2025 MOTs. Highest fail rate at 8 years old.
How the Rio Mk4 (YB) compares
At each age below, see how the Rio Mk4 (YB) holds up against other cars the same age. The averages combine all fuel types.
Based on 105,025 tests across 12 Kia models, built around 2018 (7 years old).
Fail rate is the share of MOT tests that ended in a fail. Retests count as tests. How we count fail rates Build years are worked out from age, so they are approximate. Tests counted are 2025 MOTs.
What to check before viewing
The model's most common MOT issues, turned into things you can ask about or look for.
Brake pads
High priorityAsk when the pads were last replaced and check the warning-light history.
Brake discs
High priorityAsk for the date and mileage of the last disc replacement; visually check for a deep wear lip and rust pitting on each disc.
Tyres
Worth checkingCheck tread depth across the full width on all four; uneven wear suggests alignment or suspension issues.
Vehicle-specific check
Worth checkingCheck the car’s number plate on MOT Wise to see its own MOT history and any recalls for its build years.
Other hatchbacks to compare
Other hatchbacks, with each one's figures taken at the same age as the Rio Mk4 (YB).
- 1
Ford Ka
Same body type, tested at the same age
- Fail rate
- 16.7%
- Still registered at 10 years
- 94.3%
No clear edge over the Kia Rio Mk4 (YB) on these figures.
Some figures could not be compared for these two cars. So this comparison uses the fail rate, share still registered and recalls only.
14,260 MOT tests on cars built around 2018
- 2
Honda Jazz
Same body type, tested at the same age
- Fail rate
- 10.2%
- Fail, no pass in 3 days
- 0.8%
- Dangerous
- 3.7%
- Still registered at 10 years
- 98%
Lower fail rate: 10.2%, against 13.6% for the Kia Rio Mk4 (YB), both built around 2018.
6 critical recall campaigns matching this model/build period.
21,810 MOT tests on cars built around 2018
- 3
Abarth 595
Same body type, tested at the same age
- Fail rate
- 18.3%
- Fail, no pass in 3 days
- 5%
- Dangerous
- 5.6%
- Still registered at 10 years
- 88.5%
No clear edge over the Kia Rio Mk4 (YB) on these figures.
4,000 MOT tests on cars built around 2018
- 4
Alfa Romeo Giulietta
Same body type, tested at the same age
- Fail rate
- 17.4%
- Fail, no pass in 3 days
- 2.8%
- Dangerous
- 5.7%
- Still registered at 10 years
- 92.6%
No clear edge over the Kia Rio Mk4 (YB) on these figures.
1,308 MOT tests on cars built around 2018
- Fail rate
- = the share of MOT tests that ended in a fail. Retests count as tests.
- Fail, no pass in 3 days
- = the share of MOT tests that failed and still hadn't passed 3 days later. A fail that passed a retest within 3 days, even the same day, isn't counted.
- Dangerous
- = the share of MOT tests where the tester marked a fault as dangerous. It is against the law to drive the car until it is fixed.
- Still registered at 10 years
- = the share of cars still registered (taxed or declared off the road) 10 years after they were first registered.
Recall context
6 recalls in all1 of the 6 Rio Mk4 (YB) recalls covers cars built in these years.
- 1 recall
Top concerns
- Child locks on the rear doors may not operate
For the exact car, check GOV.UK's recall checker with the number plate.
What has gone wrong on Rio Mk4 (YB) cars built around 2018
The share of petrol cars that have ever failed an MOT on each part of the car. Based on 420 cars.
Fail rate by engine size, built around 2018 (7 years old)
Engine sizes across all petrol Rio tests (not specific to Mk4 (YB)).
How Rio Mk4 (YB) cars have aged
How Rio Mk4 (YB) cars have aged
How fail rates have changed as these cars got older. Each line follows cars first registered in about the same year across several years of MOT data. Not a prediction for any one car.
Some lines cover only a year or two, so read this as a rough guide.
How each part holds up as Mk4 (YB) cars age
How each part holds up as Mk4 (YB) cars age
The share of petrol cars built 2017-2020 that have ever failed an MOT on each part of the car. Rates usually rise with age, but can dip slightly as cars leave the road.
| Part of the car | 5 years | 6 years | 7 years | 8 years |
|---|---|---|---|---|
| Suspension | 3% | 5% | 5% | 8% |
| Brakes | 5% | 11% | 9% | 11% |
| Emissions | No figure | 1% | 1% | 1% |
| Tyres | 10% | 16% | 21% | 20% |
| Lighting | 3% | 2% | 5% | 7% |
Based on petrol cars in the 2017-2020 build-year band, from 240 to 489 cars at each age.
Mk4 (YB) variants compared
Rio Mk4 (YB) variants built around 2018
The fail rate for each Rio Mk4 (YB) variant, grouped by fuel. Each row counts fails per MOT test, the same way as the main fail rate chart.
Petrol
- RIO13.3%6,649 tests
Diesel
- RIO16.1%770 tests
Most common issues on Kia Rios of this age
This list covers every Kia Rio built around 2018, whichever generation it is. We don't have a defect list for the Mk4 (YB) on its own.
Most common advisories and fails
In order of the share of MOT tests that recorded each one
- 117.3%Advisory
Tyre worn close to the legal limit or worn on the edge
- 213.2%Advisory
Tyre slightly damaged, cracking or perishing
- 38.9%Advisory
Brake pads wearing thin
- 45.0%Advisory
Brake disc worn, pitted or scored, but not seriously weakened
- 53.5%Advisory
Brake disc worn, but not excessively
Based on 7,421 tests
Looking at a Kia Rio Mk4 (YB) right now?
Enter its number plate to see its full MOT history, risk rating and running costs.
Frequently asked questions
Built around 2018 (7 years old), the Kia Rio Mk4 (YB) (2017-present) fails MOTs noticeably less often than typical for this age. This is based on 7,421 7-year-old MOT tests from DVSA data. Each retest counts as a test.