The 3.0 litre TDI V6 engine from the S5, S6 and S7 TDI has found its way to the B9 Audi S4 and S4 Avant. The mild hybrid turbodiesel is set to replace the 3.0 litre V6 TFSI petrol engine in the European market, where the new WLTP standard and fleet emission targets are hurdles.

Like on the S5 and S5 Sportback, the 3.0 TDI makes 347 PS and 700 Nm of torque. Linked up to quattro all-wheel-drive and an eight-speed torque converter automatic gearbox, the S4 TDI is good for 0-100 km/h in 4.8 seconds, a tenth faster than the wagon-bodied Avant. Top speed is electronically capped at 250 km/h.

The outgoing (for Europe) petrol motor makes 354 hp and 500 Nm, and is good for 0-100 km/h in 4.7 seconds (4.9 seconds for the Avant), so we’re looking at the same performance ballpark. It’s likely that the petrol engine would continue in other markets – we’ll wait to hear from Audi.

This electrified engine pairs a 3.0 litre V6 TDI with a 48V belt-driven starter motor and an electrically powered compressor (EPC). With a response time of under 300 milliseconds, the EPC provides “very vigorous acceleration” and repeatable boost function while accelerating.

The belt alternator starter is capable of recuperating up to 8kW of power and 60 Nm of torque. A DC/DC converter steps this voltage down for components in the 12–volt electrical system. A compact, air-cooled 0.5 kWh lithium-ion battery sits under the boot floor.

The S4 is the top, non-RS Audi A4, and is a rival to the W205 Mercedes-AMG C43. Looks a little too tame? You won’t think the same of the 450 hp full-fat RS4.


GALLERY: Audi S4 Avant TDI