"The overall diameter of any tyre fitted to an off-road passenger vehicle or commercial vehicle must not be more than 50mm larger or 26mm smaller than than of any tyre designated by the vehicle manufacturer for that model." Page 16 of NCOP 11 LS
I'm guessing that is what jasduf is referring to - in which case, why do all the tyre places make such a fuss about putting these bigger tyres on? Lack of understanding? Or does the NCOP only apply to certain states (doesn't make sense since it is NATIONAL Code of Practice).
After 15,000km I think my BFGs might be down to about 51mm larger
I'll ring up the insurance company and let them know about the tyres in another 5,000 km.