Karma_hunden said:yeah, the wheel spin ratio. LOL. you see, if you have thicker tyres in the rear than in the front (or vice versa) on an AWD that is equally turning all 4 wheels, one have more grip than the others...in other words...is like putting a 16 inch wheel in one side and a 18 on the other. just doesnt work...you will eat the crown. and your tranny will be like a redneck...toothless and screwed.