Gents

I have been running Cooper ST 265/70 x 17 on my diesel S model, with air suspension. These tyres are 803mm in diameter - compared to the 763mm diameter of your standard tyre (255/60 x 18) - and compared to 799mm for a 285/60x18.

I completed a 7000km trip with a full load (5 pax and roof rack) from Brisbane to Uluru and back via the Simpson in Sept this year, without problems, but....

The 265/70 will occasionally rub the inside of the rear guard under compression eg a load on board and some largish bumps at speed. If you look inside the rear wheel arches you will see that there is a step/projection into the arch that reduces clearance by about 50mm - and the larger tyres may contact this. I haven't experienced any tyre damage as a result of the contact, contact apppears fairly light but there is body sheet metal under the plastic wheelarch. Something to watch for.

PS: the car drove very well on gravel with the larger tyres, and we were the only vehicle to complete the trip without a flat though there were some chips out of the rears.