When photos of a new Audi test mule go into circulation, you can be sure that many, many publications will run a story and a believed S7 prototype photographed in camo this week continues to prove that point.
So what makes everyone assume this is an S7? The main clues are a larger and lower front fascia, different taillights and quad tailpipes that are a staple of Audi S-car cues. The black painted S5-look wheels might be an indicator but wheels never prove much in prototype land.
Interestingly, the mags and websites reporting seem to be all over the board on what they think will power the S7. Here's a sampling.
AutoCarEither Audi's 4.2-liter V-8 or 5.2-liter V-10 are possible, as is the W-12 engine that will be returning in the new A8 next year. There are rumors of an RS7 model as well, which would likely take the big V-10 and leave the S7 with the V-8, though it isn't confirmed either. Base A7s are expected to use Audi's new 3.0-liter supercharged V-6.
AutoblogIt is not clear how much power the S7 will have, although unconfirmed reports suggest it will be either a supercharged 3.0-litre V6 or 4.2-litre V8 with around 500bhp.
UK sales of the Audi A7 will start in March next year and a V10-powered RS variant will also be part of the range.
MotorAuthorityAs for what's housed beneath the hood, your guess is as good as ours, but something along the lines of Audi's new supercharged 3.0-liter V6 or the free-breathing 4.2-liter V8 could be in order.
So What Do We Think?The Audi S7 is expected to get a 394-horsepower 4.0-liter V-8 for motivation, and should drive all four wheels. It won't be the hottest A7-platform vehicle, however, as an RS7 with a screaming 5.0-liter V-10 twin-turbo engine derived from Lamborghini DNA providing 600-plus horsepower.
One official source we're not naming confirmed to Fourtitude that the next-gen S6 will make use of the upcoming 4.0T biturbo V8. This engine was originally developed for the A8 but wide use in other Audi models only makes sense and the S6 confirmation added with past engine sharing between S8 and S6 models suggests S8 and S7 will use the engine. Think of the 4.0T as Audi's equivalent to Mercedes 6.3 used widely by AMG. By installing the 4.0T in many cars it will help develop economies of scale in components purchasing.
Given 4.0T will be turbocharged and even a cheaper single turbo version has been rumored, wide variations of tune are likely and make estimating power for specific models nothing more than a guess. 450 hp seems as if it'd be the mark but, again, that's a guess.
Why not the 4.2? Up until now the only N/A 4.2s to go over 355 hp have been high-rev concept engines. High rev doesn't suit S6, S7 or S8 and it's likely not as fuel efficient as 4.0T either so we're ruling it out.
Why not the W12? W12 has never been an S-car engine or an RS-car engine for that matter. It's a luxurious motor for a luxurious A8 package but has a lot of mass and is not terribly sporting. More importantly, it's expensive to build and doesn't sell in the volumes Audi hopes to achieve. Sources tell us the W12's presence in the A8 is as much a move to help realize development and production cost savings for Bentley's Continental line as it is based on demand for a 12-cylinder Audi. And, that it even fits in the C-chassis sized A6 and A7 remains to be seen.
Why not the V10? We'll go out on a limb and guess the RS 7 (a car whose existence we've confirmed with our sources) may also be an even higher tune of the 4.0T. The RS application is a guess for pretty much everyone including us but the V10's absence in the S-cars is certain.
As cool as the biturbo V10 is, it's also about to go the way of the dinosaur. On a trip to Germany in late 2009 we had a chance to meet Roland Mayer of MTM and he said something that surprised us. Mayer's firm was (and likely still is) working on a biturbo V10 fitted R8 and following our inspection of the car he likened the engine to a 'high water mark' and of another era. With a market shift toward efficiency and a corporate shift to downsizing, an engine like the biturbo V10 no longer fits the market (not including exotics like Lamborghini or the R8) no matter how good it is. I later relayed Mayer's theory to quattro GmbH boss Stephan Reil when I ran into him in Frankfurt and, without going into specifics, he agreed sighting specifically the push to downsize engines.
That's a long story but it is the backbone for our theory that the biturbo V10 from the RS 6 may be the darling of editors writing for the mags and blogs above but this doesn't ensure its future. Categorically we're willing to say the biturbo V10 won't be in an S-car and though we don't have any details on RS 7 beyond its existence we're willing to guess that car won't have it either.
Read more about the S7 via the links below. Most share the same photos but in particular we'd suggest you check out MotorAuthority as their gallery also includes an interior shot.
Full Story - Motor Trend
Full Story - AutoCar
Full Story - AutoBlog
Full Story - MotorAuthority