Newbie Questions

[Triathlete]

Others will disagree.

With you? No way!

But yea...the tod is happiest if all tires are the same but as long as the bigger (within reason) tires are in the rear you are fine.
MPG...I have always used the cheapest gas I can but (inclubing in Moab where they have even lower octane levels) and have noticed no negative affects. I always get 320+ miles on a tank of gas (mostly short trips city/country driving with a bit of highway). And that is with oversize tires.

[Mile High VX]

Here is a good post on the subject:

http://www.vehicross.info/forums/sho...ght=tires+size