Originally Posted by Rydiak
You never want to mix different tires. Due to the difference in tread composition and pattern, you could prematurely unbalance one side of the car and create a hazardous situation.
I believe you are referring to never mixing different tire brands or models on THE SAME AXLE. There is no problem with running one brand or model on one axle with a different brand or model on the other axle, although IMHO I think that you get a better ride, and the car is more predictable, with 4 of the same brand and model tires on all 4 wheels.