Standard a 245/70r16 is around the limit on an range rover. I know 225/75r16 fit nicely.
With a little work common larger tyres such as 235/85r16 can be fitted. With more time, effort, cost and compromise then potentially any size tyres could be fitted.
If you are going to the effort of increasing tyre size then I would recomend going for at least a 32" tall tyre (eg 235/85r16 or 265/85r16) as this is a very common size fitted to defenders and other modefied land rovers, resulting in many ruts ending up that deep. Given the recent rise though in the number of prople using even bigger tyres, the advantage of upgrading to 32" tyres has been deminised.
Spacers can be a mixed blessing, they can push the tyre out wards so that instead of fitting nicely up into the wheel arch, they catch on the outer pannels.
Also increasing suspension travel can cause problems fitting bigger tyres. With a Gwyn Lewis challenege kit even standard 205r16 tyres of factory alloys can rub :lol:
Do note that sizes quoted in tyre side walls are only nominal figures and actual sizes can vary a fair bit.
