UHP Tires with Unsymetrical Design
 

I have two Sumitomo 285/30/18 ready to be installed on my new rims. Like most UHP tires, these have an INSIDE and OUTSIDE marking to aid in installing. The difference here is that these newer UHP tires don't have the rotation dircetion marked on them anymore though they are unidirectional tires. What I notice is that when mounted as directed (using the INSIDE/OUTSIDE guide), the left side is not a mirror of the right side - it's not simply a mirror image! I have checked my other cars with Contis and same thing. In my mind, this means confusion - uneven tire wear, poor wet traction, etc? Anyone have any thoughts on this? On the ones with symetricall threads (eg. G'Year Eagle F1-GS-D3) the direction of rotation is labeled and left/right look exactly the same when mounted. Educate me if you will. Thanks.

google nitto nt01 tires and look at their tread.... with proper alignment and suspension settings (camber, toe in and out, etc etc) the tire should sit in the "proper" spot on the driving surface, which is the only tread that will matter. when going around a corner (left or right) you will the tire will transfer some weight to the inside or outside depending on which way your going, and obviously a different tread pattern while turning left or right can help traction in that corner as to the design vs the direction of travel... at least, that's my understanding on it.

Maybe. I just don't understand how left/right threads would be different on a road going tire.

If your tires are
 

Asymetric AND directional then they come in left side and right side tires. This means different part numbers and everything. I think you have two either left or right side tires. DOH!