2018 Audi A4 — MOT failures & pass rate
78,693 MOT tests on the 2018 Audi A4 are in this dataset, and 88.4% of them passed. Executive cars of a similar age fail at 10.8%, so the 2018 A4 sits squarely on the average. Failures cluster in tyres, suspension and brakes.
What the MOT record shows
No single area dominates — tyres (5.9%) and suspension (3.7%) are close, so failures are spread across several systems rather than one weak point.
At component level the recurring items are tread depth, coil spring and brake pads — tread depth alone was recorded 2,979 times.
Mileage is the strongest signal on the record: 7.7% of 0-30k cars fail, rising to 13.5% once past 150k.
Fuel type barely separates them — petrol fails 11.4% of the time against 12.2% for diesel.
Advisories point at the next bill rather than this one: tyres was flagged on 22.4% of tests without failing them.
The trend is worsening — 9.1% of tests failed in 2021 against 15.5% in 2025, the usual pattern as a fleet ages.
How it compares
Top failure categories
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Tyres | 5.9% | 4,642 |
| 2 | Suspension | 3.7% | 2,885 |
| 3 | Brakes | 1.6% | 1,264 |
| 4 | Visibility | 1.5% | 1,138 |
| 5 | Lighting & signalling | 1.3% | 1,048 |
| 6 | Emissions & environmental | 0.5% | 425 |
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 | 2,979 |
| 2 | Coil spring | 2,632 |
| 3 | Brake pads | 1,265 |
| 4 | Headlamp aim | 1,011 |
| 5 | Wipers | 900 |
| 6 | Mounting | 385 |
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 | 22.4% | 17,618 |
| 2 | Brakes | 13.3% | 10,501 |
| 3 | Suspension | 8.7% | 6,879 |
| 4 | Other defects | 7.7% | 6,034 |
| 5 | Visibility | 3.0% | 2,363 |
| 6 | Lighting & signalling | 0.4% | 331 |
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 | 19,414 | 7.7% |
| 30-60k | 37,714 | 11.9% |
| 60-90k | 16,037 | 14.5% |
| 90-120k | 4,120 | 15.5% |
| 120-150k | 1,000 | 16.1% |
| 150k+ | 407 | 13.5% |
Failure rate by age
By fuel type
| Fuel | Tests | Fail rate |
|---|---|---|
| Petrol | 54,695 | 11.4% |
| Diesel | 23,996 | 12.2% |
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2021 | 16,402 | 9.1% |
| 2022 | 15,634 | 9.1% |
| 2023 | 15,481 | 11.6% |
| 2024 | 15,402 | 12.9% |
| 2025 | 15,774 | 15.5% |
What to check before buying a 2018 A4
On a 2018 A4, tyres is what the MOT record says goes wrong most — it appeared in 5.9% of tests. Check these areas before you commit.
- Tyres (5.9% 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.
- Suspension (3.7% of tests): Worn drop links, bushes, springs or shocks — listen for knocks over bumps and check for uneven tyre wear. Typical repair: £150–£450 per corner.
- Brakes (1.6% 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 2018 Audi A4s pass their MOT?
88.4% of the 78,693 2018 Audi A4 MOT tests in this dataset passed — a 11.6% fail rate.
What is the most common MOT failure on a 2018 Audi A4?
Tyres, recorded in 5.9% of tests, followed by suspension (3.7%).
Does the 2018 A4 get worse with mileage?
Its MOT fail rate rises from 7.7% in the 0-30k band to 13.5% in the 150k+ band.
Methodology & source. Based on 78,693 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.