Western Australian Consolidated Regulations Western Australian Consolidated Regulations (1) A vehicle with a
GVM not over 4.5 t must not have pneumatic tyres of different carcass
construction fitted to the same axle, but the tyres may have different cord
materials and a different number of plies.
(2) However,
subrule (1) does not apply to a tyre being used in an emergency as a
temporary replacement for a tyre complying with the subrule.