2018 Kia Optima — MOT failures & pass rate
The 2018 Kia Optima passed 88.5% of its 15,312 recorded MOT tests. That is effectively the same as large family cars of a similar age (12.3% fail rate), so the MOT record here is unremarkable in either direction. Failures cluster in tyres, brakes and visibility.
What the MOT record shows
No single area dominates — tyres (5.4%) and brakes (4.4%) are close, so failures are spread across several systems rather than one weak point.
At component level the recurring items are brake pads, wipers and tread depth — brake pads alone was recorded 540 times.
Condition tracks the odometer closely. Failures run at 7.0% in the 0-30k band and 15.1% in the 150k+ band, a 8.2-point spread — more than double.
The hybrid cars hold up better: 9.1% fail against 11.7% for diesel, a 2.7-point gap across 15,159 tests.
Tyres is the most common advisory, noted on 25.2% of tests — work that passed today but is likely due soon.
The trend is worsening — 8.7% of tests failed in 2021 against 12.8% in 2025, the usual pattern as a fleet ages.
How it compares
Top failure categories
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Tyres | 5.4% | 826 |
| 2 | Brakes | 4.4% | 676 |
| 3 | Visibility | 3.4% | 520 |
| 4 | Lighting & signalling | 2.8% | 427 |
| 5 | Emissions & environmental | 0.9% | 138 |
| 6 | Seat belts & restraints | 0.3% | 40 |
Most common specific failures
The exact components most often recorded as failures — more specific than the categories above.
| # | Failure item | Times recorded |
|---|---|---|
| 1 | Brake pads | 540 |
| 2 | Wipers | 483 |
| 3 | Tread depth | 451 |
| 4 | Headlamp aim | 397 |
| 5 | Washers | 144 |
| 6 | Malfunction indicator lamp | 120 |
Top advisory categories
Advisories aren't failures, but they flag work likely needed soon — useful when budgeting.
| # | Category | % of tests with advisory | Tests |
|---|---|---|---|
| 1 | Tyres | 25.2% | 3,856 |
| 2 | Brakes | 20.9% | 3,203 |
| 3 | Other defects | 8.6% | 1,317 |
| 4 | Visibility | 4.0% | 616 |
| 5 | Emissions & environmental | 1.2% | 180 |
| 6 | Lighting & signalling | 1.1% | 173 |
Failure rate by mileage
Higher-mileage cars tend to fail more — often the most useful guide to real condition.
| Mileage band | Tests | Fail rate |
|---|---|---|
| 0-30k | 2,474 | 7.0% |
| 30-60k | 6,687 | 11.5% |
| 60-90k | 3,920 | 13.5% |
| 90-120k | 1,454 | 13.0% |
| 120-150k | 493 | 13.0% |
| 150k+ | 284 | 15.1% |
Failure rate by age
By fuel type
| Fuel | Tests | Fail rate |
|---|---|---|
| Diesel | 14,232 | 11.7% |
| Hybrid | 927 | 9.1% |
| Petrol | 153 | 8.5% |
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2021 | 3,058 | 8.7% |
| 2022 | 3,128 | 11.8% |
| 2023 | 3,083 | 11.9% |
| 2024 | 3,056 | 12.5% |
| 2025 | 2,987 | 12.8% |
What to check before buying a 2018 Optima
The failure pattern for this year is specific enough to inspect against: tyres accounted for 5.4% of tests. Start there.
- Tyres (5.4% of tests): Usually a quick, known-cost fix, but check tread, age and uneven wear (which can hint at alignment or suspension issues). Typical repair: £50–£120 per tyre.
- Brakes (4.4% of tests): Pads/discs are routine wear; binding, imbalance or corroded pipes are more serious — test for pulling under braking. Typical repair: £100–£350 per axle.
- Visibility (3.4% of tests): Wipers, washers, mirrors and screen damage — usually inexpensive, but check for chips in the driver's line of sight. Typical repair: £15–£150.
Repair costs are rough UK ballpark ranges to set expectations, not quotes — actual prices vary widely by car, parts and garage.
Frequently asked questions
How many 2018 Kia Optimas pass their MOT?
88.5% of the 15,312 2018 Kia Optima MOT tests in this dataset passed — a 11.5% fail rate.
What is the most common MOT failure on a 2018 Kia Optima?
Tyres, recorded in 5.4% of tests, followed by brakes (4.4%).
Does the 2018 Optima get worse with mileage?
Its MOT fail rate rises from 7.0% in the 0-30k band to 15.1% in the 150k+ band.
Methodology & source. Based on 15,312 MOT tests. Dataset: DVSA MOT testing data (2021,2022,2023,2024,2025). Data last updated 2026-07-27. Figures reflect MOT-testable defects only — read the methodology for how these are calculated and what they don't measure.