I've got a set of pro comp 35x1250x15's on my 90 with a 2" lift but i had to fit some 30 mm wheel spacers so i could keep my turning circle less than that of the Q.E.2. Then you've got the problem of having to have your speedo adjusted because of the increase of tyre size!!!
Had similar problems myself with biodiesel in my 90 when we had a recent cold snap and found lumps of gelled biodiesel blocking the fuel filter,no more biofuel for me until i can find a cheap way of heating the fuel.