[Cartoday]
Last week Audi revealed more details on its upcoming supercharged 3,0-litre V6 engine, reportedly planned to be at the heart of the new A6 and S4.
Of course, the main cause of concern for petrolheads is the discontinuation of the 4,2-litre V8 that did services in the previous B6 and B7 generations of S4 in favour of a smaller capacity engine 
with forced induction – especially with the global attention now focused on increased fuel economy. Fortunately, Audi has been along this path before as the first generation B5 S4 was powered by a twin-turbocharged V6.At the heart of the upcoming A6, a new 3,0-litre supercharged V6 with direct injection and 1,1 bar boost is expected to produce in the region of 220 kW and 420 N.m of torque between 2 500 and 4 850 r/min. Although no details regarding power outputs are known, pundits have suggested 260 
kW for the new range-topping variant of the A4. Mated with the new dual clutch S-Tronic transmission, expect the S4 to sprint from zero to 100 km/h in less than six seconds.The spy photograph (courtesy of Carpix and Worldcarfans) of the silver car indicates that the S4’s exterior will only feature slight modifications to distinguish it from lesser models, such as quad exhaust tailpipes, redesigned bumpers and LED taillights.Just to emphasize how serious Ingolstadt’s engineers are about reducing fuel consumption, they’ve just unveiled the new Audi Valvelift System after six years of R&D. Now available on the direct-injection 2,8-litre and 3,2-litre V6 FSI engines, AVS is reportedly able to reduce thirst by up to seven percent as well as allow for smoother power build up and greater throttle response. AVS is only operational between 700 and 4 000 r/min – so constant mid-range engine speeds will achieve the best economy.Both the saloon and Avant models of the S4 will make their debuts at the Paris Motor Show in September.