Diesel engines are not so popular on the US market. But, German manufacturers, who have a long tradition in building diesels, try to change the habits of American public. For the first time, the executive class Audi S Series models are welcoming TDI power into their ranks: the new Audi S6 and S7 join the recently reinstated SQ5 in offering a V6 TDI.
Thanks to an electrically powered compressor working with a 48-volt primary electrical system, the new MHEV models combine characteristic TDI economy with exceptional throttle response which can be fully exploited with the help of S sport suspension with damping control, dynamic all-wheel steering and the option of ceramic disc-assisted braking.
An impressive 700 newton metres (516.3 lb-ft) of torque available across an engine speed range of 2,500 to 3,100 rpm is there. Pairing an electrically powered compressor with a 48-volt primary electrical system for the first time, this takes the 3.0-litre V6 TDI’s total power output to 350 horsepower, which is transmitted via the eight-speed tiptronic automatic transmission to the quattro all-wheel-drive system.
The electrically powered compressor (EPC) delivers high starting performance. As well as very vigorous acceleration, the electric supercharger provides a repeatable boost function when accelerating. This means the EPC pre-empts any hint of turbo lag.
The EPC paves the way for an impressive starting performance. The V6-TDI complete with EPC propels the new S6 Saloon from 0-62mph in 5.0 seconds, with the S6 Avant and S7 Sportback taking a tenth of a second longer over the standard sprint. The top speed is electronically limited to 155mph.
All S TDI models have homologation to the Euro 6d temp emission standard. WLTP fuel economy values for the S6 TDI Saloon range from 35.8 mpg to 36.2 mpg, equating to NEDC-correlated CO2 emissions of 164 g/km. The figures for the S6 Avant are 34.9 mpg to 35.3 mpg and 171 g/km, and for the S7 Sportback 35.3 mpg to 35.8 mpg and 170 g/km.
The S sport suspension developed specially for the new S models comes with damping control as standard, highlighting these vehicles’ sporty character. It lowers the body of the S6 by 20 millimetres, and by 10 millimetres in the case of the S7. This gives both S models the same low ride height. Adaptive air suspension – the air suspension version with adjustable damping – makes its first appearance on S models as an explicitly comfort-oriented alternative. It can be set to three modes and includes a “lift” position for poor roads and automatic levelling. In the “auto” mode the body is lowered by a further 10 millimetres at speeds of 75mph and above, and in the “dynamic” mode the vehicle remains always at this low ride height.