2018 Audi A3 — MOT failures & pass rate
150,904 MOT tests on the 2018 Audi A3 are in this dataset, and 90.8% of them passed. Small family cars of a similar age fail 10.4% of the time, so this is 1.1pp better than the group it competes with. Failures cluster in tyres, lighting & signalling and visibility.
What the MOT record shows
One area stands out: tyres, recorded in 6.2% of tests against 1.6% for the next-worst category.
At component level the recurring items are tread depth, brake pads and headlamp aim — tread depth alone was recorded 4,667 times.
Mileage is the strongest signal on the record: 6.9% of 0-30k cars fail, rising to 15.5% once past 150k — 2.2× the risk.
The petrol cars hold up better: 8.9% fail against 11.1% for diesel, a 2.2-point gap across 148,242 tests.
Tyres is the most common advisory, noted on 23.5% of tests — work that passed today but is likely due soon.
How it compares
Top failure categories
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Tyres | 6.2% | 9,281 |
| 2 | Lighting & signalling | 1.6% | 2,357 |
| 3 | Visibility | 1.6% | 2,353 |
| 4 | Brakes | 1.5% | 2,310 |
| 5 | Suspension | 0.9% | 1,346 |
| 6 | Emissions & environmental | 0.4% | 603 |
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 | 4,667 |
| 2 | Brake pads | 2,283 |
| 3 | Headlamp aim | 1,880 |
| 4 | Washers | 1,677 |
| 5 | Wipers | 942 |
| 6 | Coil spring | 684 |
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% | 35,500 |
| 2 | Brakes | 13.5% | 20,389 |
| 3 | Other defects | 6.5% | 9,746 |
| 4 | Suspension | 2.9% | 4,336 |
| 5 | Visibility | 2.9% | 4,306 |
| 6 | Road wheels | 0.4% | 598 |
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 | 50,947 | 6.9% |
| 30-60k | 72,330 | 9.7% |
| 60-90k | 22,524 | 12.0% |
| 90-120k | 4,166 | 13.0% |
| 120-150k | 761 | 12.5% |
| 150k+ | 168 | 15.5% |
Failure rate by age
By fuel type
| Fuel | Tests | Fail rate |
|---|---|---|
| Petrol | 123,224 | 8.9% |
| Diesel | 25,018 | 11.1% |
| Hybrid | 2,661 | 9.4% |
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2021 | 31,388 | 9.1% |
| 2022 | 30,404 | 8.3% |
| 2023 | 29,856 | 8.8% |
| 2024 | 29,664 | 9.8% |
| 2025 | 29,592 | 10.1% |
What to check before buying a 2018 A3
The failure pattern for this year is specific enough to inspect against: tyres accounted for 6.2% of tests. Start there.
- Tyres (6.2% 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 (1.6% of tests): Often a cheap bulb, but persistent issues can mean wiring or corrosion in the units. Typical repair: £10–£150.
- Visibility (1.6% 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 Audi A3s pass their MOT?
90.8% of the 150,904 2018 Audi A3 MOT tests in this dataset passed — a 9.2% fail rate.
What is the most common MOT failure on a 2018 Audi A3?
Tyres, recorded in 6.2% of tests, followed by lighting & signalling (1.6%).
Does the 2018 A3 get worse with mileage?
Its MOT fail rate rises from 6.9% in the 0-30k band to 15.5% in the 150k+ band.
Methodology & source. Based on 150,904 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.