For the first time, both S models in the A4 family are using a V6 diesel engine - the Audi S4 Sedan TDI and the S4 Avant TDI. The 3.0 TDI produces 255 kW (347 metric hp) of power and up to 700 Nm (516.3 lb-ft) of torque. A mild hybrid system based on a new 48-volt main on-board electrical system increases efficiency, while the electric powered compressor (EPC) ensures powerful drive-off performance. This combination of power, torque, efficiency and spontaneity is unique in the segment.
The 3.0 TDI, the most powerful configuration level in Audi's V6 diesel series, combines brawny performance with high efficiency. Its output is 255 kW (347 metric hp), and 700 Nm (516.3 lb-ft) of torque is available between 2,500 and 3,100 rpm. The V6 diesel accelerates the Audi S4 Sedan TDI from stationary to 100 km/h (62.1 mph) in 4.8 seconds; in the Audi S4 Avant TDI it is 4.9 seconds. Top speed is electronically governed at 250 km/h (155.3 mph).
The drive of the S TDI models integrates the EPC and mild hybrid technology (MHEV). Both systems are embedded in the standard 48-volt main on-board electrical system. For the first time, a powerful 48-volt belt alternator starter is the heart of the mild hybrid system in the S4 TDI, with maximum recuperation power during braking of up to 8 kW. A DC/DC converter transforms this voltage for the components in the 12-volt network. An additional compact air-cooled lithium-ion battery with a capacity of 0.5 kWh installed under the luggage compartment floor serves as the energy center.
