Nice road test report here of the new Audi S8.
Right from the off, the advanced unit feels more muscular and altogether more responsive.
On light throttle loads in third gear or higher there are no telltale signs apart from a digital read-out within the instrument binnacle that the new engine’s advanced electronic management system has chosen to close down the inlet and exhaust valves of cylinders 2, 3, 5 and 8 in the interests of fuel saving and lower emissions.
The operation of the cylinder deactivation system on the pre-production prototype we drove was absolutely seamless, both from a mechanical and acoustic standpoint. This perception is achieved, in part, by what Audi calls active noise cancellation – a system used to suppress the typical hum and what the German car maker describes as other intrusive acoustic elements of the engine when running in four-cylinder mode.
With added throttle, the delivery is uncannily smooth and extremely linear across a wide range of revs. There’s no discernible turbocharger lag of any kind, just a compelling and boundless seam of energy all the way from the 800rpm idle all the way to the 6500rpm cut-out point. And to top it all off, there’s a lovely deep burble through the exhaust that grows in intensity as you pile the revs on.