First drive: Audi’s 597bhp S8 Plus

What’s this, some special-edition trim for the greying Audi S8?

Not quite. Some miniscule styling tweaks hide a hotter S8 that develops 597bhp, which is the same power figure as the Ferrari 458 Speciale.

Not bothered yet? Okay, try this. The S8 Plus churns out 516lb ft of torque in regular service, but the bi-turbo 4.0-litre V8, as seen in Audi’s RS6 and the Bentley Continental GT, can overboost to 553lb ft for those dicier overtakes.

Which means you’re looking at the torquiest Audi in production today – R8 V10 included. An ECU remap, freer-breathing turbos and new exhaust valves unlock the V8’s extra muscle. For reference, a standard S8 has 512bhp and 479lb ft.

AMG has been lobbing silly power into S-Classes for yonks…

Very true, but they’ve not played the ace card of all-wheel drive. The S8 Plus is of course Quattro-driven, which means the sum total of those portly numbers is a 0-62mph dash of 3.8 seconds. Yep, in a massage seat-equipped limousine.

Okay, cool numbers, but what does that sort of shove feel like?

Absurd. The acceleration isn’t brutal or savage, though. The S8 just surges, the turbos puffing hard and the eight-speed auto changing up politely. You ask, it goes. No lag, no crescendo, just an extremely tractable squeeze in the back.

The eye-drying acceleration isn’t really much of an event, glib as it sounds. Don’t think of the S8 Plus as a very fast car. Think of it as a teleportation device. Hit throttle pedal, and warp to destination.

It feels right at home on the derestricted motorways of its homeland, where handling is a footnote. Here, the S8 finds its pomp, lighting the afterburners above 120mph and ripping past regular Benzes pegged at 155mph. That is, of course, if you’ve ticked the 189mph limiter option.

Optional ceramic brakes do a sterling job of stopping the Plus; the hesitant-on-downchanges eight-speed gearbox less so.

It has a V8. Does it sound any good?

At low revs, you get some decent burble, but as the revs wind up towards the 7,000rpm cutout, it’s all about the bass. An AMG S-Class or Jaguar XJR gives you more fireworks – the S8’s barrel-chested V8 is actually a touch diesely.

Don’t get me wrong – the motor’s smoother than double cream – but what with the ceiling’s active noise-cancelling microphones doing their best to keep road roar out of your earholes, Audi’s efforts to tune the engine sound around its own soundproofing aren’t ultimately convincing. At least there’s no speaker fakery going on. And you can’t tell whether it’s running on eight cylinders, or just four…

Eh? Did it break down?

No, but in a sop to economy, the S8’s engine shuts down half of its cylinders when you’re only wafting to help it achieve 28.2mpg and 231g/km on the official cycle. The parameters for half of the engine going to sleep are so brilliantly German, it seems apt to share them with you.

First off, engine temperature needs to be at 30 degrees Celcius or above. Your road speed must be at least 15mph, with engine speed between 930rpm and 3, 500rpm. Meanwhile, the engine has to be developing between 118lb ft and 184lb ft. Meet all those criteria, and cylinders 2, 3, 5 and 8 go imperceptibly offline. Makes your head hurt, doesn’t it?

Does it still ride like a barge should?

Actually, it’s pretty good. Adaptive suspension is standard, offering the usual buffet of Comfort, Auto and Dynamic modes. Leave it in Auto and despite its 21in alloys, you could legitimately potter about in the Plus as you’d hope to in any lesser A8.

An S-Class is less taut, and generally better at isolating you from the outside world – wind noise above three-figure speeds is too intrusive in the supposedly autobahn-dwelling S8.

How does it handle? Or should that be ‘does it handle’?

Despite an aluminium hybrid construction, it’s obviously quite a big, heavy car – 2,065kg, in fact – with safety-first all-wheel-drive. Not what you’d call chuckable.

More bizarrely, Audi’s chosen to offer its much-maligned Dynamic Steering on the Plus, which actively alters the response of the steering depending on your relative speed. The result is an unwieldy car that’s intimidatingly hard to place, because you’re never sure just how sharply the nose is going to hove into a bend. It’s not a standard system in the UK, so leave it alone. You’re already paying £16,315 more than a regular S8, after all…

So, is this Plus about as pointless as Audis get?

It’s only natural there’ll always be a cluster of humanity which looks at a safe, quiet and comfortable luxury saloon and says “yes, but what would it be like with twice as much power?”

If there are customers who want a limo to run sub-four seconds to 62mph, and your engineers possess the wherewithal to create it, why not give it to them? Sometimes, the sheer quantity of acceleration can be so amusing, a car worms its way into your affections. With the utterly batty Plus, you might finally have a reason to want an S8.