2,454 tests in 2025
Audi S4 reliability and MOT pass rate
86.7% passed first time. The 13.3% fail rate is 9.3 points better than the all-car average, on a median example 10 years old with 68,445 miles.
Pass rate
86.7%
22.6% of all cars failed; 13.3% of these did.
Fixed on the day
2.4%
Passed after a defect was put right during the visit.
Median at test
68,445 mi
10 years old.
Fail rate by age
| Age at test | Tests | Fail rate |
|---|---|---|
| 3-5 years | 951 | 8.6% |
| 6-9 years | 226 | 10.6% |
| 10-13 years | 242 | 12.8% |
| 14+ years | 1,004 | 18.8% |
What the S4 fails on
Share of failed tests with at least one fail item in each DVSA inspection section. A test can fail in several sections at once.
- Tyres108 dangerous37.6%
- Suspension12 dangerous35.8%
- Lamps, reflectors and electrical equipment20.5%
- Brakes26 dangerous16.5%
- Noise, emissions and leaks14.4%
- Visibility10.7%
- Body, chassis, structure10.1%
- Seat belts and supplementary restraint systems5.8%
Is the S4 getting worse?
The fail rate fell 3.3 points to 16.6% from 2022 to 2025 while the median one tested aged 2 years. Ageing alone would predict about 2.4 points, so it is holding up better than the fleet average for its age.
| Year | Tests | Median age | Fail rate | All cars | |
|---|---|---|---|---|---|
| 2022 | 1,156 | 14 | 19.9% | 22.5% | |
| 2023 | 1,125 | 14 | 17.2% | 22.8% | |
| 2024 | 982 | 15 | 18.1% | 23.2% | |
| 2025 | 1,015 | 16 | 16.6% | 22.6% |
Fail rate is first attempts at class 4 tests. Median age is the age of a typical S4 at its test that year, and it is the number to watch: across the whole fleet each extra year of age adds roughly 1.9 points to the fail rate, so a model whose age and fail rate rise together is simply getting older.
The exact defects that fail it
Every failure item DVSA recorded against a S4 in 2025, counted by how many tests each one appeared on.
- 1Condition: has ply or cords exposed45 tests
- 2Condition: has a cut in excess of the requirements deep enough to reach the ply or cords39 tests
- 3Coil spring: fractured or broken34 tests
- 4Pins and bushes: pin or bush excessively worn30 tests
- 5Ball joint dust cover: ball joint dust cover no longer prevents the ingress of dirt21 tests
- 6Tread depth: tread depth below requirements of 1.6mm21 tests
- 7Joints: constant velocity boot split or insecure, no longer prevents the ingress of dirt16 tests
- 8Brake pads: less than 1.5 mm thick16 tests
What wears out first
Advisories are the tester flagging wear that is still legal. A typical S4 collects 2.59 of them per test, and these are the ones that come up most. Treat it as the running-repairs list for the next year or two.
- 1Tread depth: tread depth below requirements of 1.6mm287 tests
- 2Pins and bushes: pin or bush excessively worn179 tests
- 3Engine oil leaks: leaking excessively from engine153 tests
- 4Brake discs: in such a condition that it is seriously weakened149 tests
- 5Brake pads: less than 1.5 mm thick129 tests
- 6Condition: has a tear, caused by separation or partial failure of its structure89 tests
- 7Sub-frame: corroded and seriously weakened79 tests
- 8Shock absorbers: has a serious fluid leak64 tests
Questions
What is the Audi S4 MOT pass rate?
86.7% of the 2,454 Audi S4 first-attempt MOTs in 2025 passed. The fail rate of 13.3% compares with 22.6% across all cars. A further 2.4% passed after a defect was fixed during the test visit.
What does a Audi S4 usually fail on?
The single most common failure is "Condition: has ply or cords exposed", recorded on 45 failed tests, followed by "Condition: has a cut in excess of the requirements deep enough to reach the ply or cords" and "Coil spring: fractured or broken". By section, tyres appears in 37.6% of failures, suspension appears in 35.8% of failures, lamps, reflectors and electrical equipment appears in 20.5% of failures.
Does age change the odds?
Sharply. At 3 to 5 years old the fail rate was 8.6%; at 14+ years it was 18.8%. The median Audi S4 tested in 2025 was 10 years old with 68,445 miles.
Is the Audi S4 getting less reliable?
The fail rate fell 3.3 points to 16.6% from 2022 to 2025 while the median one tested aged 2 years. Ageing alone would predict about 2.4 points, so it is holding up better than the fleet average for its age.
First-attempt class 4 tests, 2025, from DVSA’s anonymised MOT data (OGL v3, retrieved 2026-09-12). DVSA records newer cars trim by trim; this page adds every S4 trim together. Year-on-year figures come from the same DVSA extracts for 2026 and earlier years. Full method on the pass rates hub.
Other Audi models
Checking a particular S4?
The odds above are the model. The car in front of you has its own record: every test, every advisory, the mileage at each one.
Due a test? Find an approved MOT station near you.