Williams technical director Mike Coughlan has clearly been looking near the boundaries of the regulations to find ever more performance while designing the FW35. Today at Barcelona the car appeared with open wheel nuts, contrary to the traditional pointy ones as can be seen in the inset.
By using wheel nuts, which are btw integrated into the new Rays magnesium alloy wheels, the team can push air through the hollow wheel axle. This means that part of the air caught by the brake ducts is fed into the axle and subsequently exits outboard of the wheel, along with more hot air from the brakes coming through the rim. As ever it will be matter of compromise for Williams to determine if it is worth it to have larger brake ducts in favour or getting more flow through the wheels. Larger brake ducts will increase drag, but more flow could help the team control the wake that is created behind the wheels, creating a big impact on the efficiency of the car's floor and diffuser.