After much debate have decided on 31/11.5 Kuhmo MTs for my Disco1 on 15" rims. Before I buy the wrong wheels and end up in need of spacers, any ideas what offset I should be looking for to prevent rubbing of inside wall of the tyre? I'm obviously prepared for trimming and fitting extended arches. Am guessing it will need to be more than +30mm as this is the offset of my 0E (300tdi ES) 16"s