2021 Audi A3 S Line 40 E S-A — MOT failures & pass rate
Across 7,014 MOT tests analysed for the 2021 Audi A3 S Line 40 E S-A, the most common recorded failure areas were tyres, visibility and lighting & signalling. Its pass rate of 89.5% was below the average for cars of a similar age (91.2%). Higher-mileage examples failed more often — 18.7% in the 90-120k group versus 7.9% in the 0-30k group.
How it compares
Top failure categories
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Tyres | 8.8% | 620 |
| 2 | Visibility | 1.0% | 68 |
| 3 | Lighting & signalling | 1.0% | 67 |
| 4 | Suspension | 0.9% | 62 |
| 5 | Brakes | 0.4% | 25 |
| 6 | Seat belts & restraints | 0.3% | 24 |
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 | 140 |
| 2 | Headlamp aim | 81 |
| 3 | Shock absorbers | 61 |
| 4 | Wipers | 47 |
| 5 | Washers | 25 |
| 6 | Registration plates | 19 |
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 | 27.5% | 1,930 |
| 2 | Other defects | 6.2% | 436 |
| 3 | Brakes | 5.7% | 399 |
| 4 | Suspension | 4.3% | 303 |
| 5 | Visibility | 4.0% | 279 |
| 6 | Road wheels | 0.8% | 56 |
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 | 2,734 | 7.9% |
| 30-60k | 3,315 | 11.5% |
| 60-90k | 762 | 13.1% |
| 90-120k | 182 | 18.7% |
Failure rate by age
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2023 | 87 | 8.1% |
| 2024 | 3,466 | 10.7% |
| 2025 | 3,460 | 10.3% |
What to check before buying a 2021 A3 S Line 40 E S-A
Before buying a 2021 Audi A3 S Line 40 E S-A, focus on the areas it most often fails on. Tyres accounted for 8.8% of tests for this year.
- Tyres (8.8% 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 (1.0% 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 (1.0% 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 A3 S Line 40 E S-As pass their MOT?
89.5% of the 7,014 2021 Audi A3 S Line 40 E S-A MOT tests in this dataset passed — a 10.5% fail rate.
What is the most common MOT failure on a 2021 Audi A3 S Line 40 E S-A?
Tyres, recorded in 8.8% of tests, followed by visibility (1.0%).
Does the 2021 A3 S Line 40 E S-A get worse with mileage?
Its MOT fail rate rises from 7.9% in the 0-30k band to 18.7% in the 90-120k band.
Methodology & source. Based on 7,014 MOT tests. Dataset: DVSA MOT testing data (2021,2022,2023,2024,2025). Data last updated 2026-07-01. Figures reflect MOT-testable defects only — read the methodology for how these are calculated and what they don't measure.