2021 Audi S3 — MOT failures & pass rate
3,448 MOT tests on the 2021 Audi S3 are in this dataset, and 93.1% of them passed. Small family cars of a similar age fail 8.3% of the time, so this is 1.4pp better than the group it competes with. Failures cluster in tyres, lighting & signalling and brakes.
What the MOT record shows
One area stands out: tyres, recorded in 5.0% of tests against 1.0% for the next-worst category.
At component level the recurring items are tread depth, headlamp aim and brake pads — tread depth alone was recorded 63 times.
Mileage matters less than usual here: the 2021 S3 fails 6.7% of the time in the 0-30k band and 8.6% at 60-90k, a spread of only 1.8 points.
Tyres is the most common advisory, noted on 17.0% of tests — work that passed today but is likely due soon.
The trend is worsening — 4.8% of tests failed in 2023 against 7.3% in 2025, the usual pattern as a fleet ages.
How it compares
Top failure categories
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Tyres | 5.0% | 172 |
| 2 | Lighting & signalling | 1.0% | 34 |
| 3 | Brakes | 0.8% | 29 |
| 4 | Visibility | 0.7% | 23 |
| 5 | Emissions & environmental | 0.5% | 16 |
| 6 | Other defects | 0.3% | 11 |
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 | 63 |
| 2 | Headlamp aim | 37 |
| 3 | Brake pads | 31 |
| 4 | Washers | 19 |
| 5 | Registration plates | 17 |
| 6 | Attachment | 11 |
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 | 17.0% | 586 |
| 2 | Brakes | 8.6% | 295 |
| 3 | Other defects | 4.6% | 160 |
| 4 | Visibility | 3.2% | 109 |
| 5 | Suspension | 0.8% | 29 |
| 6 | Emissions & environmental | 0.6% | 22 |
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 | 2,037 | 6.7% |
| 30-60k | 1,337 | 7.0% |
| 60-90k | 70 | 8.6% |
Failure rate by age
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2023 | 147 | 4.8% |
| 2024 | 1,625 | 6.7% |
| 2025 | 1,670 | 7.3% |
What to check before buying a 2021 S3
The failure pattern for this year is specific enough to inspect against: tyres accounted for 5.0% of tests. Start there.
- Tyres (5.0% 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 (1.0% of tests): Often a cheap bulb, but persistent issues can mean wiring or corrosion in the units. Typical repair: £10–£150.
- Brakes (0.8% 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.
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 S3s pass their MOT?
93.1% of the 3,448 2021 Audi S3 MOT tests in this dataset passed — a 6.9% fail rate.
What is the most common MOT failure on a 2021 Audi S3?
Tyres, recorded in 5.0% of tests, followed by lighting & signalling (1.0%).
Does the 2021 S3 get worse with mileage?
Its MOT fail rate rises from 6.7% in the 0-30k band to 8.6% in the 60-90k band.
Methodology & source. Based on 3,448 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.