JUST HOW MUCH power does a Porsche 911 need? Back in 1963 it had two air-cooled litres, 128bhp and 174 Newtons slung out behind its rear wheels, numbers that though paltry today were more than respectable then, making the original 911 rapid if worryingly twitchy on bends and in the wet.
Some 51 years later, the Turbo S I'm driving has a 3.8-litre, water-cooled, twin-blown, direct-injection, six-cylinder boxer engine that develops 552bhp (some 200bhp more than a 911 Carrera) and a maximum 750Nm available for 20 seconds on overboost – which to me looks like enough twist to reduce a reasonably sized residence to rubble, were one inclined to attach a hefty tow-rope to the car's tail and tug. Yet in spite of the massive motive force behind me, I detect not even the remotest threat that I might disappear suddenly and disastrously into the scenery whenever I put the hammer down, as might well have occurred in even some relatively recent 911s.
That composure and predictability result from continuous developments over the past half century that have transformed a relatively humble sports car – and one that possesses the inherent shortcoming of having its engine in the “wrong” place – into one of the most iconic automobiles ever made, a genuine supercar easily capable of holding its own in the superficially more glamorous company of Ferraris, Lamborghinis and, more recently, McLarens. And such is the way of things at Porsche that Turbo versions of the current 911 (which devotees of the marque tend to refer to by its factory designation of 991) aren't merely fitted with that far more potent motor, but are also the recipients of a raft of major technical upgrades over and above the standard car.
All-wheel-drive has, of course, been a given on the German company's hero model since the mid-‘90s, when it began its gradual transformation from scary monster into smooth operator, but the latest Turbo S is fairly loaded with hightech trickery. This includes dynamic chassis control that helps minimise body roll, active suspension management, and 1.5-degree electromagnetic rear-axle steering (which increases manoeuvrability by turning against the front wheels at speeds below 50km/h, and improves agility by turning them in the same direction above 80km/h).
The list continues with an active aerodynamics package that comprises a three-way-variable front spoiler and rear wing that adjust to provide extra downforce in Sport mode – though you'd need to be travelling at warp-factor speeds to appreciate those particular benefits. Rear track has been widened by 7cm, resulting in improved grip and a considerably more cursive rump when compared with the regular 911 Carrera. And even the four-wheel-drive system differs from that of the Carrera 4's, with hydraulic control providing more precise torque vectoring to each wheel.
While several of the above features are shared by both Turbo and Turbo S models, the latter also gets boosts in power and torque of almost 40 horses and Nm respectively, as well as enhanced active suspension, dynamic engine mounts, standard Sport Chrono Package (denoted by the dash-mounted digital/analogue stopwatch), and lightweight carbon-composite brakes, with 410mm-diameter discs at the front and 390 at the rear.
Unlike with lesser 911s, there's no choice of transmissions for the Turbo and Turbo S, which like it or not are fitted with a sevenspeed PDK (Porsche Doppelkupplung – in other words, dual-clutch) set-up offering automatic or manual shifting, Sport mode and, with the Chrono package, launch control. Fortunately, the PDK is one of the best boxes of its kind, shifting fast and seamlessly in Drive, and so apparently in tune with whoever's at the steering wheel that when the console-mounted selector is slotted to the Manual position it's a joy to flip up and down the ratios using the paddles, sensing the instant response as each gear is engaged.
There is, to be honest, a slight suggestion of turbo lag at low revs, but as the crankshaft spins towards 2,000rpm, this is rapidly replaced by a detonation of kinetic energy that hurtles the car forward in a rolling thunderstorm of power and torque. The latter is so huge and sustained that in third or fourth there's really no necessity to shift to another gear – unless, of course, the tachometer's sprinting towards the 7,200rpm red line, which does tend to happen rather often in a car as extraordinarily fast as this.
I should add here that it's also a cinch to drive the Turbo S slowly, though I realise this isn't exactly the point of a machine that accelerates from 0-100km/h in 3.1 seconds (several testers claim to have shaved a couple of tenths off that, a testament to its superb all-wheel-drive traction), twice that speed in less than 10 and finally runs out of breath at 318km/h. Yet at 50km/h in “D”, with the needle hovering on or just under “1” on the rev counter, I'm astonished to register the PDK has slipped into seventh gear, so flexible and untemperamental is the boxer engine. Stop-start doubtless contributes to Porsche's claimed thirst of 10.3km/l, though it does self-cancel once “S” is selected from the menu of powertrain modes, a point at which fuel consumption generally nosedives anyway.
In terms of handling, the Turbo S may lack a little of the immediacy of its lesser brethren in the 911 family, though this is entirely commensurate with its role as a continent-devouring grand tourer, as opposed to the hard-core, street-racing GT3 that serves as Porsche's other halo car in the line-up. So while it's easily sharp enough to involve and sufficiently predictable to reassure – partly due, no doubt, to the 991's extended wheelbase that's enabled a subtle forward repositioning of the engine – it doesn't feel quite as engaging or as nimble as the 911 S I essayed on the Leipzig test track early last year.
Grip and stability on the dry roads on which I'm driving are as impressive as I'd assumed, and while the stopping power of the carbon-ceramic discs verges on the unbelievable, ride is perhaps a tad on the rigorous side. That, however, is ameliorated by a cabin that over the years has become ever more luxurious, and on this test car means 18-way-adjustable sports seats, red and black leather (a colour combination I'm beginning seriously to like), Alcantara roof and pillars, and Bose sound system, not to forget the superlative, intuitive, driver-oriented ergonomics that we've come expect from Porsche.
It means that while the Turbo S is devastatingly fast, it's also sophistication personified – a missile of a motorcar that's nonetheless so comfortable, refined and easy to drive it really can be used every day. The proposition sounds tempting, but as your licence is on the line whenever you turn the key, you might also be pondering my original question as to how powerful your 911 needs to be. Because the manifold pleasures of owning this most potent Porsche would surely be tempered by constant fears of unwelcome missives from the boys in blue. And that's exactly why, for the next few weeks at least, I'm steering well clear of my mailbox.