Kia Niro 2021: reliability & common MOT faults

At a glance

How 22,687 first tests went in 2025.

Passed first time: 87 in every 100
Did not pass first time: 13 in every 1002,842 failed first-attempt tests
The typical car: 4 yearsabout 36,159 miles
First tests counted: 22,687

What failed most often

Tyre condition (rear)22 in every 100 failed tests
Windscreen wipers (front)18 in every 100 failed tests
Tyre tread depth (front)11 in every 100 failed tests

How we count this. Data: UK MOT open data, 2025. Only Class 4 cars on their first MOT of the year are counted. A car that fails and is fixed at the test station still counts as a fail in the first-attempt rate. These are raw results, not adjusted for age, mileage, or peer mix. The MOT does not test engine or gearbox internals.

Advisories

Other things testers noted as worn or close to failing, more often than on similar cars.

An advisory is a note from the tester about something that has not failed yet. It is an early warning, not a fail.

Suspension arm pins and bushes (rear)

Noted on 42 first tests4.2 times as often as similar carsElevated evidence

Data: UK MOT open data, 2025. Counts cover advisories recorded on failed first tests only, compared with cars of the same age and mileage.

MOT pass rates

How first tests ended, and how the pass rates are counted.

Passed first time: 87in every 100; Passed on the first test.
Fixed at the station: 4in every 100; Failed, then fixed at the test station the same day.
Failed: 9in every 100; Did not pass, and were not fixed at the test station.

First-attempt pass 87.5% of 22,687 first tests (2025): only cars that passed first time count. Official-style pass 91.0%: cars fixed at the test station also count as a pass. The 4 fixed and the 9 not fixed make the 13 in every 100 that did not pass first time.

By fuel type

First testsTypical mileagePassed first time, as testedPassed first time, same mileage

Electric11,76640,879 miles8687

Hybrid10,91831,780 miles8989

Figures are in every 100 first tests. Cars with more miles usually fail more often, so the same-mileage figure gives every fuel the mileage mix of all the cars in this year.

Same model, other years

Passed first time in every 100, all tested in 2025.

Newer cars are younger, so look for a jump rather than the climb. A year earlier (2024), when these cars were a year younger, 88 in every 100 passed first time.

Year	Passed first time	First tests
2016	84 in every 100	1,188
2017	84 in every 100	4,067
2018	86 in every 100	6,079
2019	86 in every 100	8,770
2020	86 in every 100	17,538
2021 This car	87 in every 100	22,687
2022	88 in every 100	22,596

If you are buying one

What this year's MOT record means for the decision in front of you.

Mileage makes a modest difference on a 2021 Niro.

Of 2021 Niro vehicles with under 23,000 miles, 91 in every 100 passed their 2025 MOT first time. With 58,000 miles or more, 85 in every 100 did.

Under 23,0004,728 tests

91

23,000–32,0004,544 tests

88

32,000–42,000 Typical car4,510 tests

87

42,000–58,0004,381 tests

86

58,000 and over4,524 tests

85

Which fuel?

	Typical mileage	Passed first time, as tested	Passed first time, same mileage
Electric	40,879 miles	86	87
Hybrid	31,780 miles	89	89

Figures are in every 100 first tests. Hybrid cars look better on the raw figures only because electric cars have done more miles (typically 40,879 against 31,780). At the same mileage there is no clear difference between the two.

What to check at your mileage

How often each fault turned up on a failed first test, by the car's mileage. Read it as: what is likely to need looking at on a car like the one in front of you.

	Under 23,000	32,000–42,000	58,000 and over
Tyre condition (rear)	1.2	3.2	3.2
Windscreen wipers (front)	1.5	2.7	2.1
Tyre tread depth (front)	0.7	1.4	1.7
Headlight aim	0.6	0.8	0.8
Number plate lights	0.1	0.1	1.0

Faults per 100 first tests, by the car's mileage at the test.

When a car fails

60in every 100

of failed cars had one item to fix.

12in every 100

of failed cars had three or more items to fix.

4in every 100

of all first tests had a defect the tester marked dangerous (unsafe to drive away).

Every figure here is a first-attempt MOT rate from DVSA open data for this model line, for cars of this model year tested in 2025. Each mileage band holds a fifth of the tests. MOTs do not test engine or gearbox internals, so this is a pre-purchase checklist, not a full reliability score.

FAQs

Short answers about how to read this model-year guide.

Is the 2021 Kia Niro reliable?

The 2021 Kia Niro follows the pattern of the model years either side. Its main cause of failure was Tyre condition (rear), about 22 in every 100 failed tests. In 2025, 87.5% of 22,687 first MOTs on the 2021 Kia Niro passed first time (PRS: items fixed at the station the same day, counted as a fail). The official-style rate including PRS is 91.0%. Among 2,842 failed first-attempt MOT tests (test year 2025), we highlight MOT failure patterns that show up more often than on cars of a similar age and mileage when the sample is large enough to trust. There is no single reliability score here; this is a pre-purchase checklist built from DVSA open data, not a guarantee for any individual car.

What is most likely to fail on a 2021 Kia Niro?

Ranked by how often they were actually recorded, the items that most often failed a 2021 Kia Niro at the first attempt were Tyre condition (rear) (21.6%), Windscreen wipers (front) (18.1%) and Tyre tread depth (front) (11.0%), each as a share of the year's failed first attempts. That is what goes wrong most often on the car. The common faults table shows a different measure: faults that are unusual compared with similar cars.

How should I read advisories vs fails?

Advisories flag issues noted at the test and are not a fail rate. We show advisory patterns that appear more often than on similar cars among failed first-attempt tests, separate from common failure rows. Use them as early-warning checks, not as a pass/fail score.

What does this Kia Niro 2021 MOT report cover?

This page highlights MOT failure patterns for the 2021 Kia Niro (registration year) using UK DVSA open data for the selected test year. Patterns are compared with cars of a similar age and mileage. It is a buyer checklist from MOT defect statistics, not a full service history or manufacturer service-bulletin list.

Does this include engine and gearbox problems?

No. MOT tests do not cover engine internals, gearboxes, or many electronic modules. Patterns here come from MOT defect statistics only and should not be read as engine or gearbox reliability scores.

About this data

How this page is built and what it can (and can't) say.

These figures come from UK MOT open data for this model year. We surface common failure patterns against similar cars, not a full reliability score, and not a pass/fail verdict on any individual vehicle.

2024 2025

What we include

UK Class 4 cars only. Normal MOT tests (not retests); first test per vehicle per calendar year; results pass, PRS, or fail.

Same-day repairs

PRS means the car 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.

How we compare

We compare this model year with other Class 4 cars of similar age and mileage in the same test year. This model family is left out of the peer group so the car is not measured against itself.

What this does not cover

MOTs do not cover engine internals, gearboxes, or many electronics; this is not a full reliability score.
Common faults come from MOT defect stats, not manufacturer TSBs or recalls.
Age and mileage matching reduces, but does not remove, differences in how cars were used and maintained.
If the data for a car is too thin to say anything useful, we say so rather than guess.

Contains public sector information licensed under the Open Government Licence v3.0.