2009 Audi S4 — MOT failures & pass rate
787 MOT tests on the 2009 Audi S4 are in this dataset, and 85.8% of them passed. Executive cars of a similar age fail 21.8% of the time, so this is 7.5pp better than the group it competes with. Failures cluster in suspension, lighting & signalling and tyres.
What the MOT record shows
No single area dominates — suspension (5.3%) and lighting & signalling (4.5%) are close, so failures are spread across several systems rather than one weak point.
At component level the recurring items are headlamp aim, coil spring and brake pads — headlamp aim alone was recorded 31 times.
Condition tracks the odometer closely. Failures run at 15.8% in the 30-60k band and 9.9% in the 120-150k band, a 5.9-point spread.
Advisories point at the next bill rather than this one: suspension was flagged on 23.0% of tests without failing them.
The trend is improving — the fail rate fell from 16.2% in 2021 to 13.6% in 2025, as the worst-kept examples leave the fleet.
How it compares
Top failure categories
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Suspension | 5.3% | 42 |
| 2 | Lighting & signalling | 4.5% | 35 |
| 3 | Tyres | 4.2% | 33 |
| 4 | Brakes | 3.0% | 24 |
| 5 | Emissions & environmental | 2.4% | 19 |
| 6 | Visibility | 1.7% | 13 |
Most common specific failures
The exact components most often recorded as failures — more specific than the categories above.
| # | Failure item | Times recorded |
|---|---|---|
| 1 | Headlamp aim | 31 |
| 2 | Coil spring | 30 |
| 3 | Brake pads | 17 |
| 4 | Tread depth | 14 |
| 5 | Catalyst emissions | 11 |
| 6 | Malfunction indicator lamp | 10 |
Top advisory categories
Advisories aren't failures, but they flag work likely needed soon — useful when budgeting.
| # | Category | % of tests with advisory | Tests |
|---|---|---|---|
| 1 | Suspension | 23.0% | 181 |
| 2 | Tyres | 17.7% | 139 |
| 3 | Brakes | 12.7% | 100 |
| 4 | Other defects | 8.1% | 64 |
| 5 | Emissions & environmental | 7.0% | 55 |
| 6 | Lighting & signalling | 4.1% | 32 |
Failure rate by mileage
Higher-mileage cars tend to fail more — often the most useful guide to real condition.
| Mileage band | Tests | Fail rate |
|---|---|---|
| 30-60k | 38 | 15.8% |
| 60-90k | 266 | 11.3% |
| 90-120k | 346 | 17.1% |
| 120-150k | 101 | 9.9% |
Failure rate by age
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2021 | 167 | 16.2% |
| 2022 | 171 | 16.4% |
| 2023 | 155 | 11.6% |
| 2024 | 154 | 13.0% |
| 2025 | 140 | 13.6% |
What to check before buying a 2009 S4
On a 2009 S4, suspension is what the MOT record says goes wrong most — it appeared in 5.3% of tests. Check these areas before you commit.
- Suspension (5.3% 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.
- Lighting & signalling (4.5% of tests): Often a cheap bulb, but persistent issues can mean wiring or corrosion in the units. Typical repair: £10–£150.
- Tyres (4.2% 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.
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 2009 Audi S4s pass their MOT?
85.8% of the 787 2009 Audi S4 MOT tests in this dataset passed — a 14.2% fail rate.
What is the most common MOT failure on a 2009 Audi S4?
Suspension, recorded in 5.3% of tests, followed by lighting & signalling (4.5%).
Does the 2009 S4 get worse with mileage?
Its MOT fail rate rises from 15.8% in the 30-60k band to 9.9% in the 120-150k band.
Methodology & source. Based on 787 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.