From `2016` to `2019`, the `S4 B9` moves the `S4` line further upmarket without losing its role as a fast saloon you can use every day. Against a BMW 3 Series, it relies on a very modern package: turbo `V6`, `tiptronic`, `quattro`, sober presentation and genuine ability to cover distance quickly. On the used market it often inspires confidence through its modern feel, but it remains a technical car that needs invoices and a complete road test.
The key issue is the `EA839` `3.0 TFSI`, most often in `CWGD` form, with `tiptronic` and sometimes a sport differential depending on specification. This engine can be very convincing, but you need to read cooling properly, boost build-up, engine mounts, leaks, turbocharging behaviour, oil-service quality and the overall state of the gearbox. A nice connected car that feels quiet on a short drive tells you nothing if the mechanical history is vague.