Etlsport however
Oh and Tom4bren your arguement fails to take into consideration the vehicle suspunsion. With the independent suspension and the weight of the vehicle all pushing downward the small diference in tire size does not affect the AWD. Its not like a solid suspenion where if you set the VX down on a flat surface the tire that is 2mm smaller in diameter (which means since the tire is attached at the center the tire is only half the diameter difference) the tire would not hover 1 mm above the surface. The suspension would still push the tire doan and contact would be solid. The radius is actual what should be measured. Heck a 1-2 mm difference would probably not be much different than driving on a paved road surface that is crowned.