420bhp is sure to attract any driver's attention, so the chance to drive three cars fitted with this turbo-charged petrol engine was an easy sell for Audi.

Motors went to Munich recently to put the latest engine technology from the premium German carmaker to the test on the roads around the Bavarian capital and, of course, on the Autobahn.

The TFSI engine is a newly developed twin-turbo V8 that pushes out 550nm of torque. Twin scroll turbochargers ensure that the car can get from 0-100km/h in a truly rapid 4.6 seconds. Average fuel consumption is a little over 29mpg (9.6l/100km in ECE mode) and while this is high by average car standards, it is very impressive in a performance car. 29mpg is roughly what a full-size diesel SUV would deliver if driven carefully, so how is Audi managing this mpg with a 'Quattro' four-wheel drive, high performance car?

There is a stop/start system and, more interestingly, 'Cylinder on Demand'. This is a new system from the German carmaker where cylinders are deactivated when not needed at speeds above 30km/h, thereby reducing fuel consumption. So, when you are pottering along, the car uses just half the engine. Under your right foot you really cannot sense the big 4-litre V8 running on just four cylinders (1, 4, 6 and 7). When you kick down on the accelerator the car springs to life with real gusto and all eight cylinders firing. Power is delivered in a creamy way via the automatic gearbox.

The 7-speed S-Tronic has steering wheel paddle shifts which are great for enthusiastic driving. A Quattro sports differential is available and essential for making really serious progress. As we know, it is fairly easy to make a car go quickly by throwing horsepower at it, but stopping a performance car is vitally important and not all fast cars stop as well as they should. S buyers can rest assured the standard brakes are very good, with optional carbon brakes ideal for track day merchants.

The V8 is simply joyous, no matter which of the body types you drive – I love the Avant, as you can squirrel away so much kit in it. When you press hard on the accelerator the car pauses for a nanosecond as if to say 'here we go' and then whoosh - you're off down the road at an impressive pace. The noise made by the exhaust pipe baffles is wonderful and primal.

Speaking of noise, Audi has launched its version of active noise cancelling (ANC). Similar to the technology used in noise cancelling headphones, unwanted sonic frequencies are done away with in the cabin. The sonic frequencies that resemble road and cabin noise are detected by clever electronic wizardry and minimised by generating a noise cancelling waveform. Very clever.

The OTR (on the road) price in Ireland is dependent on specification but starts at €86,900 for the S6; the S6 Avant is an additional €3,150. The S7 get the sports differential as standard and a few other toys and weighs in at €107,540. The range-topping S8 starts at €130,540 - over seven grand less than the car it replaces!

So the S6 and S7 are massively capable cars with impeccable manners - and at the same time they can invigorate. I love them.

Michael Sheridan