Tried the search but didn't find anything. I was thinking of removing the spare to save a little weight. Currently, I have Victoracers mounted on stock wheels that I drive to the local autox. I was wondering if I got a flat front or rear, would using the spare cause any damage do to slight size differences. If it will, I will leave the spare at home. If it doesn't, I will take it with me.

TIA

 

Stock front and rear are 0.2 inches different in diameter. If your victoracers are comparable, you'll be fine. If the difference is bigger - well, so far as I can tell nobody has any idea what the stock differential can take without issue.

 

I haven't had my spare in the car for over 20,000 miles... A AAA card is much lighter

 

I'm not sure if you're wanting to NOT have the spare in the car (saves weight and lowers the CG a little bit, worth doing) or if you're concerned with using the spare in conjunction with the Kumhos. If the latter, use the same strategy as with the stock tires - use the spare in front and the front tire to replace the flat rear. The smaller diameter of the spare could do damage to the diff.

 

I agree with Jeff, use the spare in the same manner as you would use it with the OEM tires.

Here's a variation of this scenario. A few days ago I noticed a nearly flat left rear tire as I was leaving my garage. So, in order to avoid all that tire switching when using the spare, I simply temporarily installed one of the rear wheels that I use for autocrossing (Kumho V700). I was interested to note that when accelerating the car pulled left, and when braking the car pulled to the right. I would have excpected the opposite - I guess I really don't understand traction and tire dynamics enough. Can anyone explain this phenomenon?