The Audi S5 will switch from a turbocharged V6 petrol engine to a 345bhp mild-hybrid V6 diesel.
The powertrain, which will be used in both the coupe and Sportback versions of the S5, is the same as that introduced on the latest S6 and S7 models. It combines a 3.0-litre TDI diesel with a 48V mild-hybrid system and electrically-powered compressor, and produces 516lb ft of torque between 2500 and 3100rpm.
The diesel engine allows the S5 coupe to achieve 0-62mph in 4.8secs, the five-door Sportback version being 0.1secs slower. Both models are electronically limited to 155mph.
The 3.0-litre petrol V6 previously used in the S5 had a slightly greater output with 349bhp, although, at 369lb ft, it produced significantly less torque. Audi also claims the new unit consumes 19 per cent less fuel than the previous petrol version, at a claimed 45.56 mpg. That figure was calculated on the NEDC test cycle, derived from WLTP values.
The S5 retains an eight-speed tiptronic gearbox, along with permanent all-wheel-drive and a self-locking centre differential.
The TDI-powered S5 will go on sale in Europe in May, with a starting price in Germany of €65,300 (£56,590). UK pricing has not yet been set.
The 3.0-litre TFSI petrol engine will continue to be offered in the S5 in some markets outside of Europe.