Northern Territory Consolidated Regulations Northern Territory Consolidated Regulations(1) A vehicle with a GVM not over 4.5 tonnes 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.