hi all , i have a near new michelin 4x4 tyre which was the spare on my 2000 td4 , they don't make these tyre's anymore , i have the new michelin scyrones ? on the rear ( pair ) and two michelin 4x4 worn on front , can i put the new-ish 4x4 and a new scyrone on the front or back ? or do you have to fit the same tread patten/tyre type - ie buy 2 new tyres and 4x4 back on the spare rack 