This is interesting...

"The new Kumhos also have different tread patterns at front and rear to cope with the differing requirements. Kumho says “The front tyres have been designed to provide the most agile cornering and cope with the sudden forces of braking while the rear tread optimises drive off turns.”

Seems a lot of effort for a street tyre interesting idea though.

Edit: beaten.

Ps. A lot of cars have different front and rear tyres, not tread (at least not from the factory, seems to be standard fitment on all SS utes though :P) but width etc