Okay, I know with AWD it's best to replace tires in pairs because of the differentials and differing tread depth will reek havoc on the diffs....

right?

Well, I have Kuhmo Ecsta ASTs on the wear bar, and I caught a nail in the tire of one of them. I guess I ran on a flat for a while and when I plugged it up, I've got 3 bulges on the sidewall. Well, I'm going to a drag/autocross race this memorial day weekend and I have found two stock Yokos I could roll on until I can get all new tires.

My question is this...

Are there any concerns or bad things to worry about with rolling with 2 all seasons up front and two summer tires in the rear? With drag racing or auto cross? I figured I'd rather ask before I go tearing around and destroying my car 6 hours from home.

Something just tells me that there has to be something bad especially drag racing if two of your wheels hook and the others spin...

 

Yep, I would NOT do that. Diffs will not be happy.

I would not AX on that anyway, even if at same tread depth. Car would handle terribly.

Drag - yep, you will have 2 spinning and 2 gripping. Not great.

 

Not a good idea mixing those types of tires together. Design, compound, overall diameter, etc won't match which means an unhappy car and handling till all matches.

Matching Tires on Four-Wheel Drive And All-Wheel Drive Vehicles