Fix the overlap! ;-)

When you work on a UV map, you can choose to view only the mesh for a selected shading domain. Engage that option so you only are working with the tire tread. The mesh in the UV tool can be manipulated directly on screen to better adjust it to match texture maps. You can select multiple vertexes and polygons, or one at a time and move, scale and rotate them. 

The typical industry trick for identifying problem areas is lay a texture map into the color channel and then make sure that your UV display options are set to show texture maps. This way you can precisely align polys to map features.

Attached is the map that I use.

You're bumping into a limitation of high detail in displacement - the computer must chew on it for awhile. Another argument for modeling low poly options and then using the vertex modelers Smooth option.