2018 Toyota Prius — MOT failures & pass rate
The 2018 Toyota Prius passed 93.8% of its 71,403 recorded MOT tests. That is 4.4 percentage points better than small family cars of a similar age, which fail at 10.7%. Failures cluster in lighting & signalling, tyres and visibility.
What the MOT record shows
No single area dominates — lighting & signalling (4.3%) and tyres (3.8%) are close, so failures are spread across several systems rather than one weak point.
At component level the recurring items are wipers, tread depth and registration plate lamp(s) — wipers alone was recorded 1,839 times.
Mileage is the strongest signal on the record: 4.5% of 0-30k cars fail, rising to 8.6% once past 150k.
Tyres is the most common advisory, noted on 13.5% of tests — work that passed today but is likely due soon.
The trend is worsening — 5.6% of tests failed in 2021 against 7.3% in 2025, the usual pattern as a fleet ages.
How it compares
Top failure categories
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Lighting & signalling | 4.3% | 3,058 |
| 2 | Tyres | 3.8% | 2,707 |
| 3 | Visibility | 2.7% | 1,951 |
| 4 | Suspension | 1.5% | 1,073 |
| 5 | Brakes | 1.3% | 900 |
| 6 | Road wheels | 0.2% | 149 |
Most common specific failures
The exact components most often recorded as failures — more specific than the categories above.
| # | Failure item | Times recorded |
|---|---|---|
| 1 | Wipers | 1,839 |
| 2 | Tread depth | 1,769 |
| 3 | Registration plate lamp(s) | 1,045 |
| 4 | Headlamp aim | 828 |
| 5 | Rear fog lamp | 749 |
| 6 | Brake pads | 734 |
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 | 13.5% | 9,670 |
| 2 | Brakes | 6.5% | 4,602 |
| 3 | Suspension | 3.2% | 2,291 |
| 4 | Other defects | 3.0% | 2,161 |
| 5 | Visibility | 1.9% | 1,387 |
| 6 | Lighting & signalling | 1.3% | 903 |
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 | 9,034 | 4.5% |
| 30-60k | 18,057 | 5.5% |
| 60-90k | 14,520 | 6.1% |
| 90-120k | 10,732 | 5.9% |
| 120-150k | 7,973 | 7.1% |
| 150k+ | 11,064 | 8.6% |
Failure rate by age
By fuel type
| Fuel | Tests | Fail rate |
|---|---|---|
| Hybrid | 71,311 | 6.2% |
| Other | 54 | 9.3% |
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2021 | 11,635 | 5.6% |
| 2022 | 12,767 | 5.8% |
| 2023 | 14,670 | 6.0% |
| 2024 | 15,523 | 6.1% |
| 2025 | 16,808 | 7.3% |
What to check before buying a 2018 Prius
The failure pattern for this year is specific enough to inspect against: lighting & signalling accounted for 4.3% of tests. Start there.
- Lighting & signalling (4.3% of tests): Often a cheap bulb, but persistent issues can mean wiring or corrosion in the units. Typical repair: £10–£150.
- Tyres (3.8% 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.
- Visibility (2.7% 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 Toyota Priuss pass their MOT?
93.8% of the 71,403 2018 Toyota Prius MOT tests in this dataset passed — a 6.2% fail rate.
What is the most common MOT failure on a 2018 Toyota Prius?
Lighting & signalling, recorded in 4.3% of tests, followed by tyres (3.8%).
Does the 2018 Prius get worse with mileage?
Its MOT fail rate rises from 4.5% in the 0-30k band to 8.6% in the 150k+ band.
Methodology & source. Based on 71,403 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.