The 4.8is conundrum

[mparker]

Aryte lads,

Bought My 3rd x5 an immaculate 4.8is. been driving her for a year now and have had nothing but gruelling beastly pleasure, until recently when she was booked into the stealer for smoking. weeks pass on and no word from the stealer until last week recieve a call....Dear sir, i would like to notify you that your car will be with us for another two weeks as BMW has approved replacing you r engine.........SAY WHAT ???

At 136000 km with motorplan expiring at 140000km this could'nt have come at a better time. .

I have a challenge though, unlike most 4.8is drivers i do take the lady out for off-roading every so often and down south in africa the terrain tend to get a little rough. The tyres of the 4.8is is a 315/35/20 (standard) and are no good for off-road applications (Michelin Diamaris)

Now i've been told i cant get an off-road tyre in that size.....and the only reccomendation is to change my rims to a smaller size, which i dont wanna do......

any reccomendations guys......pleeeeze