A yes to both. A smaller tire has to spin faster to go the same distance. I can't say how much it will change things, but the smaller you get, the more it will have an affect on the system. Also, you will be losing ground clearance. If that even matters to you.
Honestly, you sound like you are in the same boat as I am. Trying to save a buck any way you can. However, I really recommend staying with the manufacturers recommend tire size.
Let me know if you have other questions.
Joe
Sunday, September 20th, 2009 AT 7:56 PM