Porsche has been building the Cup Race Cars with Center-Lock wheels and hubs for quite some time. Advantage? Faster tire changes in the pit and small but measurable unsprung weight savings. They brought this technology to the street cars with the introduction of the Carrera GT in 2004 but, being as though only 1,270 cars were built, this technology was never really experienced by the general population of Porsche owners.
These locking wheel fasteners are unique: They are made from 7075 aluminum alloy and feature a free-spinning titanium cone that allows for bind-free seating/torquing. The assembly also incorporates a spring-loaded locking mechanism that prevents unwanted loosening.
A close-up of the wheel fastener and cap. Installing these requires a unique torque procedure. Special lubrication, tools and attention is required!! Don't try to do it yourself unless you're trained and have the right equipment. Doing so could result in breakage issues that you read about on the forums.
This is a close-up of the hub assembly with the wheel removed. Note the red studs in lug bolt holes- these help keep with wheel located and secure.