Formula One cars must have four, uncovered wheels, all
made of the same metallic material, which must be one of two magnesium
alloys specified by the FIA. Front wheels must be between 305 and 355mm
wide, the rears between 365 and 380mm.+
With tyres fitted the
wheels must be no more than 660mm in diameter (670mm with wet-weather
tyres). Measurements are taken with tyres inflated to 1.4 bar. Tyres may
only be inflated with air or nitrogen.