Subtle changes to a classic supercar

EVERYTHING happens for a reason, if your belief system lies somewhere between the fatalist and the determinist.

this notion merely helps the human brain cope with the completely randomness of the universe.

But putting the philosophy aside for one moment, it is true that a chance occurrence can help you make sense of something previously confusing.

This idea perfectly describes the existence of the Porsche 911 Carrera 4. Whether you plump for the standard 4 or the 4S, you are paying a premium over the two-wheel drive Carrera 2 and 2S that also nets you subtly different rear bodywork (including a unique light arrangement and a wider track) and the inevitable gains in traction that an extra pair of driven wheels brings.

But the question mark comes simply because the two-wheel drive Carrera is a devastatingly effective machine already.

If there’s one thing it’s not lacking that is traction; the rear-engined arrangement maximising the available grip when powering out of a bend.

Not forgetting that your new 911 comes with the hugely effective Porsche Active Stability Management (PASM) system to help you out in a tight spot. So why would you choose a Carrera 4? Well, unlike previous Carrera 4s, the 991-generation is a lot closer visually to the two-wheel drive version.

In the past, the extra width at the rear has been known to unbalance the overall shape and leave it looking like it was carrying a little too much Christmas indulgence around its behind.

But now it’s been perfectly judged, and it carries a little more muscle to arguably make it more visually appealing than the Carrera 2. And that rear light signature might seem like a small thing but it catches the eye and makes you wonder why every 911 doesn’t have it.

Mechanically the differences between the 4 and the 2 are straightforward. You get the same sonorous 3.4- or 3.8-litre flat six engine with two outputs (standard and S model) and a choice of seven-speed manual or seven-speed PDK dual-clutch gearbox.

A further trick of its sleeve is a double de-clutch facility which can be switched on or off; essentially in manual-equipped cars it will blip the throttle for you on downchanges to match the revs to the wheel speed, thereby avoiding any nasty locking of wheels when really pressing on. But the majority of this is under the skin, so you climb aboard the 911 and be greeted by the same appealing cabin, much improved over the outgoing car in both ergonomics and material quality.

With several bits pinched from the Cayenne and Panamera, it has a more grown-up feel, and the reassuring snap and click of the switches gives the impression that it will last as long as the bulletproof mechanicals.

There’s nothing to indicate that this 911 is four-wheel drive as you pull away. In fact, the Carrera 4 diverts most or all of the power to the rear unless it detects a loss of grip, so you have the four-wheel drive only when you need it. That means it drives exactly how you would want it; namely just like a two-wheel drive 911.

You sacrifice nothing in terms of the slickness, sensitivity and accuracy in the way that the car responds to your inputs. You don’t feel any additional weight, nor that the car is compromised as a result. Sure, there is a modest weight penalty but that’s offset by the increased traction. Where you really feel the benefit is when conditions aren’t ideal - namely most of the time - and the reassurance of four-wheel drive gives greater confidence.

You can exploit the Carrera 4S’s mighty flat-six more of the time; hear that distinctive engine note rise and fall but accelerate harder and sooner out of the bends.

On the higher-powered S version, you get torque vectoring as standard, which can switch power between wheels on the same axle as well as front to back. It’s fiendishly clever but all you really need to know is that it punts you out of a corner with as much traction as it can possibly muster.

And when you do get caught out by an unseen change of surface or even something as dramatic as an unhelpful spillage on the road, the Carrera 4 can switch the power from front to rear or vice versa in 100 milliseconds. You still have complete awareness of what’s going on beneath you - there’s just a little more happening to help you out.

It’s for this precise reason that the four-wheel-drive version makes the 911 even more of a practical, everyday supercar.