[Trackrash]

Originally Posted by darrin

I'm not an expert (and don't play one on tv either), but as I understand it different tire models have different sidewall characteristics/friction coefficients/grip/etc. that can negatively effect the car's balance and potentially produce unpredictable handling at/near the limits. Tires are designed to be run as a "system" --

True, but remember the front and rear are different sizes any way.

I have done it both ways. On the street or casual track use different front and rear brands or models is probably not an issue.

If you are competing or running at your maximum at an autocross, DE or actually racing, different story.