Sitting at the top of Audi's saloon family is the A8. Give it a sporty makeover and it becomes the S8. Give that a bit of a tweak and a boost and you arrive at the Audi S8 Plus, the most powerful saloon that Audi has ever put on the road.
And by the most powerful, we mean 605 pferdestärke.
We've previously said that the A6 is rather stately, but for the A8 family, that's exactly what it is. The regular A8 is a large executive saloon, with the A8L offering more space for VIP transport. It's perhaps with that target market that the S8 avoids the full RS treatment, instead walking a more delicate path, preserving the prestige of this VIP cruiser.
Audi S8 Plus: Elegant design
There's a formula in current Audi design that's resulted in a strong family identity. It flows from the A4 through the A6 and into the A8 and into this S8 Plus. At this top level, however, things are more understated. This isn't a model that screams horsepower in your face like some of Audi's RS models, and we can't help feeling there's a point to that: it's a subtler touch, for an owner who doesn't want to be as showy.
There's the addition of carbonfibre body details in places, with the option to change the added (but small) boot lip spoiler from body coloured to carbon. The same can be applied to the wing mirror covers, and the rear lights are darkened, sitting above the S8 badges.
Around the front the nose gets a slight tweak with a lowered front apron with carbon trim, and a move to black for the grille, away from the standard chrome. There's also an exclusive paint colour for the Audi S8 Plus, a silver with matt effect.
What the Audi S8 Plus hangs onto is its stately elegance. The S8 Plus isn't too big for its frame, it doesn't look bloated or ungainly, but there's no escaping that this is a serious looking car.
It's more meaty around the front than the BMW 7 Series, although there's a sharper drop in the rear roof line, meaning less rear window space than BMW's big saloon. Both the Audi and the BMW are more serious in posture than the Mercedes S Class, with the AMG models offering a healthy rivalry to Audi's S8 Plus in the performance executive saloon class, although this Audi undercuts the AMG in price quite nicely.
Audi S8 Plus: Sumptuous interior
If we've one criticism of Audi interiors, it can be that things can get a little samey. Sit in the interior of the A1 and you could be in the A6 Avant, depending on where you're looking.
The TT broke this mould some, the R8 followed suit, but at the executive end of the spectrum in this S8 Plus (as with the A/S/RS7) you get a lift. The interior of the S8 Plus changes the switch gear, the layout and the finish, making it stand out from many of Audi's cars. This is a competitive space too, having enjoyed the interior of BMW's high-tech 7 Series, there's plenty to fight for.
The heavy application of leather meets glossy piano black trim. Normally we baulk at glossy interiors because they're a fingerprint magnet, but if you're going to do it, do it like Audi. The glossy centre console shouldn't work, but as we sat in the driver's seat, we couldn't help but gaze across it.
There are a lot of controls and buttons, especially to control the media system and the climate control, but the arrangement makes you feel like you're piloting a jet. You may as well be, with that much power on tap, but the use of a handled drive select lever helps reinforce this feeling.
The brushed steel finish to the buttons, and stainless steel pedals brings a lift to a dark interior, with grey dials presenting your essential speed and revs. The centre of the driver's display is all digital, so can carry mapping or entertainment information from the MMI system, all of which can be controlled via the steering wheel, but you don't get the full digital treatment as you do on the Audi TT.
Love the blinds in the Audi S8 Plus pic.twitter.com/Kzpmpqg9ol— Chris Hall (@christhall) April 15, 2016
For the rear passengers, powered blinds sit inside the double-glazed privacy glass, giving more protection from the sun, making it a peaceful place to ride. There's also active noise cancellation in the interior, as well as a boosted 14-speaker Bose sound system as standard. The back seats are ridiculously comfortable and you'd expect nothing less.
Audi S8 Plus: On the road
Slip into the driver's sport seat of the S8 and you'll notice that visibility is excellent and it's very comfortable. That will be welcome news for those who'll be driving his nibs in the back and we love that there's a central arm rest that's adaptable for both the driver and the passenger separately.
Finger the start button and the awakening roar of the 4-litre V8 will send a tingle down your spine. This is a boosted version of the standard S8 which offers 520PS, which, frankly speaking, is nowhere near enough power. In reality, that lift to 605PS means that the S8 Plus will hit 62mpg in 3.8 seconds, over the measly 4.1 seconds of the standard model.
Just pause and think about that for a few seconds. Yes, that's about how long it takes to hit the legal speed limit. The Audi S8 Plus is speed limited to 155mph, but you can have that limit lifted to 189mph if you opt for the Dynamic Package. That, importantly, adds the fade-free carbon ceramic brakes, hence the £9250 price.
While his lordship fingers his copy of Horse and Hound in the backseat, this vast saloon will eat the road as it launches itself into the horizon. From the driver's seat it's almost inexpressibly satisfying. There's little or no delay as you put your foot down and the speed hits you like a hammer.
The S8 Plus squirms when you hit the pedal hard, all four wheels delivering power and dynamically fighting to keep grip and keep you heading in the right direction. You'll feel this brutal ballet through the steering wheel, driven by that snarling orchestral V8, but you don't feel out of control.
It differs from the tight precision of the Audi R8. The clean delivery of power is breathtakingly fast in Audi's supercar, but feels potently aggressive in this twin turbo saloon, it's muscly and brutal.
But the Audi S8 Plus manages that side of the car with panache. If you're just popping to Waitrose to buy more saffron, then cylinder on demand and the comfort mode will get you there as smoothly as any limo. It's quiet, it's peaceful, it's almost sedate, as well as being wonderfully plush.
Turn the corner, return to Dynamic mode and floor it, and you're back in a sports car, with tightened suspension and heavier steering making you lord of the road. While the R8 might be ridiculously assured in corners with effortless control and grip, the S8 Plus perhaps surprises: it doesn't wallow like a hearse, despite the size.
Then you have all the technology to keep you safe. Lots has been said about collision avoidance and autonomous systems on other cars, but Audi has been doing this for a long time. Adaptive cruise control will vary your speed in traffic to keep you a safe distance from the car in front - handy in motorway cruising - and pre-sense front will detect potential accidents and alert you, before taking measures, like pre-loading the brakes and tightening the seatbelts.
This latter system we got to test, when a tractor emerged into the road on a corner with no warning. The S8 Plus audibly alerted us so we could dab the brakes and take action.
The Audi S8 Plus is in some ways a marvel. It's expensive, sure. It costs £97,715 for starters, boosted to £108,115 as seen here, but as we said, most of that extra comes from the added Dynamic package with carbon brakes. The performance numbers are impressive, especially in context of the AMG rivals, with the S63 some £20k more expensive.
You might think that all that power would just mean that the S8 Plus is expensive to run. Well, at 28mpg (Audi's figures), it is. Even with cylinder on demand reducing the load, this saloon is a long way from the more efficient diesel options of the regular A8.
The Audi S8 Plus is going to be for the few. It's a blend of sports car performance with luxury limo comfort and priced as such. However, the S8 Plus is a marvellous car to drive. If this is on your list, just make sure you're sat up front where the fun is, rather than languishing in the rear.