2021 Audi S4 Black ED TDI Mhev Quattro A 3.0L Diesel · SW71 PSO

The 2021 Audi S4 Black Edition TDI MHEV Quattro presents a clean MOT history over its recent testing cycle, with both the November 2024 and November 2025 inspections passing without any advisories or defects recorded. This indicates a stable maintenance trend, with no signs of recurring issues or deteriorating components over the past year. The absence of even minor advisories—such as tyre wear, fluid leaks, or suspension wear—suggests the vehicle has been well maintained within the MOT testing parameters, at least up to the 36,113-mile mark. For a buyer, this is a positive indicator of mechanical reliability, though it does not preclude the need for a thorough pre-purchase inspection, particularly given the car’s hybrid powertrain and quattro drivetrain. The mileage accumulation of 6,112 miles between the two MOT tests (from 30,001 to 36,113) aligns with typical usage patterns for a vehicle of this age, averaging around 7,223 miles per year over its five-year lifespan. There are no red flags in the mileage progression—no sudden spikes that might suggest aggressive driving or neglect, nor prolonged periods of inactivity that could imply storage-related issues. The most recent test in November 2025, just eight months prior to this evaluation, confirms the car remains within its annual MOT compliance window, though buyers should verify if any servicing or minor repairs were conducted outside the MOT framework, as these are not recorded in the official history. Given the absence of historical defects, a pre-purchase inspection should prioritise components less frequently scrutinised in MOT tests but critical for long-term reliability. The hybrid powertrain—particularly the electric motor, inverter, and high-voltage battery cooling system—should be checked for any signs of overheating, fluid leaks, or unusual noises, as these are not routinely assessed in standard MOTs. The quattro drivetrain’s differentials, especially the rear unit, warrant close examination for fluid leaks or abnormal wear, while the suspension—particularly the coil springs, anti-roll bars, and bushings—should be inspected for signs of fatigue or corrosion, especially if the car has been driven on rough roads. Additionally, while the MOT history is flawless, a detailed brake system assessment is advisable, including the condition of the rear brake calipers, which are prone to binding in high-performance Audis, and the integrity of the brake discs for uneven wear or heat cracking. Finally, the structural underbody and wheel arches should be checked for corrosion, particularly in salted or rural environments, as this can compromise safety without being flagged in standard tests.