Originally Posted by m4a1mustang

The v12s are directional so check to see if they were mounted correctly. Still, you're going to feel a difference in handling with two different makes of tires on the car. You really shouldn't mix and match sets like that.

Also, as with all new tires, you're going to have to go about 500 miles with normal driving to completely wear away the mold release coating on the tire, so traction will not be optimal initially. Also, since you are going from a worn tire with little tread to a fresh tire with a lot of tread you are going to notice a bit of squirm because of all that extra tread.