Audi’s upcoming new S4 – caught here in saloon and Avant forms, shorn of any disguise and with a current RS4 in tow – may look just as you’d expect it to, but it will be a radically different car compared to the one it replaces. Ignore the to-be-expected lowered ride height, subtle body kit, 18-inch alloys and quad exhaust pipes, because the big news is under the bonnet.
While the outgoing S4 uses a naturally aspirated 4.2-litre V8, when the new S4 makes it debut at the Paris motor show this autumn, it will be powered by supercharged 3.0-litre V6 powerplant.
I don’t get it. Why the change for the new Audi S4?
Easy – the downsizing move aims to lower emissions and consumption without penalising performance. A smart move as fuel prices spiral ever upwards. The V6 engine is also said to be lighter to sharpen the S4’s dynamic balance.
Although the engine is smaller, don’t expect Audi to give an inch in the power wars – the forced-induction V6 will generate at least 350bhp and 406lb ft, more than matching the old S4’s 340bhp output and ahead of BMW’s 335i (306bhp/295lb ft) and the Mercedes C350 (268bhp/258lb ft). Expect a five second blast to 60mph and a limited 155mph top speed. Of course, the S4 will feature Audi’s four-season quattro drivetrain.
And we hear that the RS4’s superb V8 will be dropped in favour of a more heavily tuned version of the blown V6 when it arrives in 2009. Pity…
Click ‘Next’ below to read more about the new supercharged Audi S4
Tell me about the supercharger, then…
Audi’s engineers have worked on developing a very compact Rootes-type supercharger that, along with its intercooler, fits snugly between the cylinder banks. And having the blower so close to the engine’s intake and exhaust plumbing has, our sources tell us, resulted in a car with a crisp throttle response and no discernable off-boost lag. We’ll see when we drive it later in the year.
Anything else new?
Like the S5, the new S4 will use Audi’s seven-speed double-clutch transmission, capable of shifting cogs in just 200ms. Despite being heavier (it weighs 40kg more than the outgoing S4’s 102kg six-speed manual box) and having a torque limit of 406lb ft, the box offers significant advantages over the manual, with quicker shifts boosting performance and earlier upshifts slashing emissions and consumption.
Downsizing for better economy without sacrificing performance sounds like a smart move, but we can’t help wondering why Audi has chosen the supercharged route, when it has such an acclaimed history of turbo charging. Click ‘Add your comment’ below and have your say.