Pragmatism meets passion in all-wheel-drive 911
Ehrenhausen, Austria — In the morning, sunshine. By noon, it's pouring buckets. By mid-afternoon, there's so much snow the road is barely visible, and the trees are sagging under the weight. An hour or two later, it's all melted and gone — go figure. It's still early autumn in the hills north of Graz, but at times like this nothing less than an all-wheel-drive car makes sense.

For more than 20 years, all-wheel drive has been a staple in the Porsche 911 line, and for good reason. Besides helping to tame the physics-challenging position of the engine (it hangs out back, aft the rear axle), it has played an important role in morphing the 911 into one of the world's most pragmatic sports cars. All-wheel drive has proven to be a popular choice too — every other 911 sold in Canada has the system, and virtually all 911s sold in Austria, Switzerland and other areas of Northern Europe are ordered with it.

All-wheel-drive evolution

2013 Porsche 911 Carrera 4 Cabriolet(Photo: Justin Couture)

Regardless of which model you choose — the Carrera 4 with its 3.4-litre, 350-hp six-cylinder, or the 3.8-litre 4S with an even 400 hp — the basic all-wheel-drive system is the same. Dubbed Porsche Traction Management (PTM), it builds on the system used in the outgoing 911 Turbo, but thanks to software upgrades, it is faster-acting and even more seamless in the way it shifts power between the front and rear axles.

Up to 100 per cent of power can be shifted to either end of the car in 100 ms — less time than can be detected by the driver — and the way it splits power varies continuously depending on speed, traction levels, and driver inputs. Typical German obsessiveness in the engineering department has seen the system drop five kilos in weight, meaning upgrading from a Carrera 2 to a 4 will net you but 50 kilos (80 lb.) on the scale; however, thanks to intensive use of aluminum, electric power steering and other key changes, the new 911 Carrera 4 weighs some 65 kg less than the outgoing model.

PTM works in conjunction with PTV (Porsche Torque Vectoring), which further divides power between the left and right rear wheels to compensate for understeer and oversteer for neutral and secure handling. An option on the Carrera 4 and standard on 4S, it features a mechanical locking differential to divvy up the power; cars equipped with the optional seven-speed PDK dual-clutch automated manual feature an upgraded version of the system called PTV Plus, which uses an electronically controlled differential.

The look is in the details

2013 Porsche 911 Carrera 4S Coupe(Photo: Justin Couture)

Unless you've spent hours gazing intensely at the new 911, it is pretty difficult to pick it apart from others in the lineup — at least from the front and side. Carrera 4 and 4S models get a new front bumper, and around the side the lower rocker panels feature plastic cladding. It's much easier to tell from the rear, where the car's swollen fenders have ballooned by 44 mm to accommodate wider rear tires and a wider stance on the road. But the easiest way to pick out the all-wheel-drive car is to look for the thin red ribbon that bridges the two triangular tail lights.

Elsewhere, there are other upgrades available to the 911 for 2013. A sliding glass panoramic sunroof is sure to appease those waiting for the Targa model, while Porsche Active Safe introduces low-speed collision detection on cars equipped with radar cruise control (PDK only). For those with truly deep pockets, there's also the Powerkit option on the Carrera S, which fits new cylinder heads and pistons, plus other goodies, to bump power to 430 hp, and slash its 0-100 km/h time to four seconds flat. You'll have to really want the extra juice, as it'll set you back more than $20k.