CENTRE-LOCKING WHEELS
This motorsport-inspired locking system for lightweight wheels is ever-more prevalent among the 911’s elite lineup. Here’s how it works
Like many innovations on Porsche road cars, the centre-lock wheel’s origins lie in motorsport. The need for a quick and efficient tyre change necessitated a new design concept where only one large nut needed to be undone to free the wheel, rather than the five smaller nuts commonly found around the middle of any wheel ever fitted to a 911. It’s worth noting wheels with a single, central mechanism to secure them to the car have been around for years (take your pick from a number of British vehicles in the mid-fifties, for example), but Porsche’s centre-locking system is more relevant for the modern world.
The ‘explained’ side of this column is, this issue, rather straightforward. This is because the simple difference between a centre-lock and a traditional alloy wheel lies at its centre: whereas a typical wheel on a Porsche is secured to a car by tightening five bolts or lugs into the wheel hub behind it, a centre-lock simply has a single, larger nut which tightens to a central thread. It has a toothed outer surface which the torque wrench fits to (via a special tool that comes with all cars fitted with centrelock wheels from factory). The wheel then ‘locks’ to the hub via a locking pin.
The first Porsche road car to make use of centre-locking wheels was the Carrera GT in 2003, followed by the 997.2 GT3 in 2009. The arrival of the
997 GT2 RS and Turbo S at the turn of the last decade started a trend that Porsche maintains to this day, whereby any of its GT (including GTS) or
Turbo 911s come factory-fitted with the technology. It is therefore easier today to count the 911 models that don’t have centre-lock wheels, rather than those that do.
Devoid of any lug holes, few can deny the beauty of a centre-locking Porsche wheel, but while the design is wholly efficient in motor racing, it’s less so for everyday use on a road-based 911. For example, if you find yourself in a position at the side of the road where a wheel change is necessary, even with the torque adapter tool, you still need a large torque wrench and breaker bar with you, as centre-lock wheels are torqued to a mighty 600Nm. Cool to look at then, but the standard Porsche five-lug wheels trump it for practicality on the road.
“Few can deny the beauty of a centre-locking Porsche wheel”