2021 Audi A3 — MOT failures & pass rate
Across 45,506 MOT tests, the 2021 Audi A3 recorded a 91.2% pass rate. That is effectively the same as small family cars of a similar age (8.3% fail rate), so the MOT record here is unremarkable in either direction. Failures cluster in tyres, lighting & signalling and visibility.
What the MOT record shows
One area stands out: tyres, recorded in 6.8% of tests against 1.2% for the next-worst category.
At component level the recurring items are tread depth, headlamp aim and shock absorbers — tread depth alone was recorded 1,028 times.
Mileage matters less than usual here: the 2021 A3 fails 7.2% of the time in the 0-30k band and 10.8% at 120-150k, a spread of only 3.6 points.
The petrol cars hold up better: 7.9% fail against 10.6% for diesel, a 2.7-point gap across 32,678 tests.
Tyres is the most common advisory, noted on 25.1% of tests — work that passed today but is likely due soon.
The trend is improving — the fail rate fell from 16.3% in 2021 to 8.9% in 2025, as the worst-kept examples leave the fleet.
How it compares
Top failure categories
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Tyres | 6.8% | 3,074 |
| 2 | Lighting & signalling | 1.2% | 536 |
| 3 | Visibility | 1.1% | 486 |
| 4 | Suspension | 0.8% | 341 |
| 5 | Brakes | 0.5% | 215 |
| 6 | Seat belts & restraints | 0.4% | 163 |
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 | 1,028 |
| 2 | Headlamp aim | 534 |
| 3 | Shock absorbers | 313 |
| 4 | Washers | 269 |
| 5 | Wipers | 244 |
| 6 | Registration plates | 147 |
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 | 25.1% | 11,436 |
| 2 | Other defects | 6.6% | 3,022 |
| 3 | Brakes | 6.1% | 2,795 |
| 4 | Suspension | 4.9% | 2,207 |
| 5 | Visibility | 3.4% | 1,540 |
| 6 | Road wheels | 0.5% | 226 |
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 | 22,417 | 7.2% |
| 30-60k | 19,386 | 9.6% |
| 60-90k | 3,050 | 13.3% |
| 90-120k | 543 | 18.1% |
| 120-150k | 83 | 10.8% |
Failure rate by age
By fuel type
| Fuel | Tests | Fail rate |
|---|---|---|
| Petrol | 28,843 | 7.9% |
| Hybrid | 12,828 | 10.1% |
| Diesel | 3,835 | 10.6% |
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2021 | 49 | 16.3% |
| 2023 | 779 | 5.3% |
| 2024 | 22,340 | 8.8% |
| 2025 | 22,329 | 8.9% |
What to check before buying a 2021 A3
The failure pattern for this year is specific enough to inspect against: tyres accounted for 6.8% of tests. Start there.
- Tyres (6.8% 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.
- Lighting & signalling (1.2% of tests): Often a cheap bulb, but persistent issues can mean wiring or corrosion in the units. Typical repair: £10–£150.
- Visibility (1.1% 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 2021 Audi A3s pass their MOT?
91.2% of the 45,506 2021 Audi A3 MOT tests in this dataset passed — a 8.8% fail rate.
What is the most common MOT failure on a 2021 Audi A3?
Tyres, recorded in 6.8% of tests, followed by lighting & signalling (1.2%).
Does the 2021 A3 get worse with mileage?
Its MOT fail rate rises from 7.2% in the 0-30k band to 10.8% in the 120-150k band.
Methodology & source. Based on 45,506 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.