2018 Infiniti Qx30 — MOT failures & pass rate
The 2018 Infiniti Qx30 passed 91.5% of its 447 recorded MOT tests. That is 2.5 percentage points better than all cars of a similar age, which fail at 11.0%. Failures cluster in tyres, lighting & signalling and visibility.
What the MOT record shows
No single area dominates — tyres (3.6%) and lighting & signalling (3.1%) are close, so failures are spread across several systems rather than one weak point.
At component level the recurring items are headlamp aim, tread depth and washers — headlamp aim alone was recorded 12 times.
Mileage matters less than usual here: the 2018 Qx30 fails 8.3% of the time in the 0-30k band and 10.9% at 60-90k, a spread of only 2.6 points.
Advisories point at the next bill rather than this one: tyres was flagged on 23.5% of tests without failing them.
The trend is worsening — 4.5% of tests failed in 2021 against 14.1% in 2025, the usual pattern as a fleet ages.
How it compares
Top failure categories
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Tyres | 3.6% | 16 |
| 2 | Lighting & signalling | 3.1% | 14 |
| 3 | Visibility | 1.3% | 6 |
| 4 | Brakes | 1.3% | 6 |
| 5 | Suspension | 1.1% | 5 |
| 6 | Emissions & environmental | 0.7% | 3 |
Most common specific failures
The exact components most often recorded as failures — more specific than the categories above.
| # | Failure item | Times recorded |
|---|---|---|
| 1 | Headlamp aim | 12 |
| 2 | Tread depth | 9 |
| 3 | Washers | 5 |
| 4 | Brake pads | 4 |
| 5 | Malfunction indicator lamp | 3 |
| 6 | Position lamp | 3 |
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 | 23.5% | 105 |
| 2 | Brakes | 10.7% | 48 |
| 3 | Other defects | 3.6% | 16 |
| 4 | Visibility | 2.0% | 9 |
| 5 | Suspension | 1.1% | 5 |
| 6 | Lighting & signalling | 0.4% | 2 |
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 | 168 | 8.3% |
| 30-60k | 219 | 8.2% |
| 60-90k | 55 | 10.9% |
Failure rate by age
By fuel type
| Fuel | Tests | Fail rate |
|---|---|---|
| Diesel | 390 | 8.7% |
| Petrol | 57 | 7.0% |
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2021 | 89 | 4.5% |
| 2022 | 90 | 5.6% |
| 2023 | 91 | 8.8% |
| 2024 | 85 | 9.4% |
| 2025 | 92 | 14.1% |
What to check before buying a 2018 Qx30
On a 2018 Qx30, tyres is what the MOT record says goes wrong most — it appeared in 3.6% of tests. Check these areas before you commit.
- Tyres (3.6% 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.
- Lighting & signalling (3.1% of tests): Often a cheap bulb, but persistent issues can mean wiring or corrosion in the units. Typical repair: £10–£150.
- Visibility (1.3% 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 Infiniti Qx30s pass their MOT?
91.5% of the 447 2018 Infiniti Qx30 MOT tests in this dataset passed — a 8.5% fail rate.
What is the most common MOT failure on a 2018 Infiniti Qx30?
Tyres, recorded in 3.6% of tests, followed by lighting & signalling (3.1%).
Does the 2018 Qx30 get worse with mileage?
Its MOT fail rate rises from 8.3% in the 0-30k band to 10.9% in the 60-90k band.
Methodology & source. Based on 447 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.