I have a SU ultra light with a 2.5 turbo Subi. My front tires are 6.80 x 15

Other than the clearance problems are there any other reasons no to go to a larger tire?
I don't have power steering.
I've talked to some people that have done this not on an SU car and they said it make a big improvement.

Thanks

You can run 8.50 or 8.80 front tires with no power steering, and gain some ground clearance as well as a little more sidewall for more cush ride. i am not sure what the difference is between the two tires size wise but they are very similar.

Go with either size. You will get a much better ride and clearance. Let me know I might upgrade to the 10.75. My 8.5 are almost new. Bigger front tire the better. All the chop from sand ruts is much smoother. Do a seach there is lots of info already on this topic.