2021 Audi Q4 — MOT failures & pass rate
The 2021 Audi Q4 passed 89.9% of its 8,137 recorded MOT tests. Against mid-size SUVs of a similar age (8.2% fail rate), the 2021 Q4 comes out 2.0pp worse. Failures cluster in tyres, visibility and lighting & signalling.
What the MOT record shows
Tyres dominates the failure mix at 8.6% of all tests — 7.2 points clear of visibility, so it is the first thing to check.
At component level the recurring items are tread depth, headlamp aim and washers — tread depth alone was recorded 206 times.
Mileage matters less than usual here: the 2021 Q4 fails 9.2% of the time in the 0-30k band and 11.6% at 90-120k, a spread of only 2.4 points.
Advisories point at the next bill rather than this one: tyres was flagged on 25.5% of tests without failing them.
The trend is worsening — 6.7% of tests failed in 2023 against 9.8% in 2025, the usual pattern as a fleet ages.
How it compares
Top failure categories
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Tyres | 8.6% | 696 |
| 2 | Visibility | 1.4% | 111 |
| 3 | Lighting & signalling | 1.3% | 109 |
| 4 | Seat belts & restraints | 0.6% | 48 |
| 5 | Suspension | 0.4% | 36 |
| 6 | Other defects | 0.3% | 26 |
Most common specific failures
The exact components most often recorded as failures — more specific than the categories above.
| # | Failure item | Times recorded |
|---|---|---|
| 1 | Tread depth | 206 |
| 2 | Headlamp aim | 119 |
| 3 | Washers | 69 |
| 4 | Wipers | 47 |
| 5 | Registration plates | 37 |
| 6 | SRS malfunction indicator lamp | 36 |
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 | 25.5% | 2,075 |
| 2 | Other defects | 7.0% | 572 |
| 3 | Suspension | 2.4% | 195 |
| 4 | Visibility | 2.1% | 174 |
| 5 | Brakes | 1.8% | 144 |
| 6 | Lighting & signalling | 0.3% | 20 |
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 | 3,720 | 9.2% |
| 30-60k | 3,861 | 10.7% |
| 60-90k | 509 | 12.8% |
| 90-120k | 43 | 11.6% |
Failure rate by age
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2023 | 45 | 6.7% |
| 2024 | 4,038 | 10.6% |
| 2025 | 4,050 | 9.8% |
What to check before buying a 2021 Q4
On a 2021 Q4, tyres is what the MOT record says goes wrong most — it appeared in 8.6% of tests. Check these areas before you commit.
- Tyres (8.6% 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.
- Visibility (1.4% 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.
- Lighting & signalling (1.3% of tests): Often a cheap bulb, but persistent issues can mean wiring or corrosion in the units. Typical repair: £10–£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 2021 Audi Q4s pass their MOT?
89.9% of the 8,137 2021 Audi Q4 MOT tests in this dataset passed — a 10.1% fail rate.
What is the most common MOT failure on a 2021 Audi Q4?
Tyres, recorded in 8.6% of tests, followed by visibility (1.4%).
Does the 2021 Q4 get worse with mileage?
Its MOT fail rate rises from 9.2% in the 0-30k band to 11.6% in the 90-120k band.
Methodology & source. Based on 8,137 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.