So I got a flat that ripped up the inner lining of my passenger rear side tire last night and had to replace the tire today, just 10 days before I run my car in my first autocross event! I'm just wondering if this will have any significant effect on traction and handling. The older rear tire remaking on the car has 8000mi of usage and has 2mm less tread depth then the brand new tire. This measurement of tread depth remains constant on each individual tread at 2mm less than the new tire at any place on the tire I checked. Any input on the effect of traction and handling? Thanks in advance for your comments.

 

I had to do this last year. Any time you are on the throttle it will pull hard to the more worn tire, so you adjust for it with steering. Once you are off the throttle, since you corrected with steering, it will pull hard to the other side, so make sure you catch it. Kind of hilarious, somewhat dangerous, and I don't really recommend for driving on the street. You should be able to find a tire shop that will shave down the new tire to match your other one.