Is it safe for a Donut?

Well, regardless of their rating. I've seen a few POS cars around here drive with them on for a year without blowing out. So, as risky as it is, someone could probably pull it off.

But hell....I drive a Cougar. Saving a couple of pounds on each wheel isn't going to do anything for the other 3900lbs my pig is carrying. :(
 
You could do it and be fine. There are alot of cars running VW beetle tires as skinnys and run 130+. Passing tech at a good track wont be possible and running a mini spare as a race tire is just about as ricer as ricer gets. Buy some draglites or prostars if you have to run skinnys up front.
 
I realy dont see a problem for a few uses at the track. Ive seen people use spares at the track. I wouldnt go driving around all the time with them on, but now and then use, I wouldnt worry at all.