Newbie Questions

[Mile High VX]

And great tip about replacing them all at once. I usually don't do that

This something that you will always need to do...the TOD system is very particular about the tires all being the same size. So if you dirve 30,000 miles on a 60,000 mile tire and have an unrepairable tire failure you'll need to replace all 4 and not just the one.

Also, if you ever have a flat on the rear you will need to put one of the front tires on the rear and the spare on the front.

If you don't do these things the TOD will create quite the issue for ya'.

[circmand]

needing to be the same I had all different sized tires on it. Same size from factory but from 3/32 to 8/32 and 2 other measures all at the same time. I never heard one peep from the TOD system. I always had the 2 largest on the back and two most worn on the front. I still think it is a good idea to keep it close. if you do get a new one maybe get it shave a mm or 2 but considering the OEM spare is a different size I think this is overhyped.

Others will disagree.

Also I have run premium and regular unleaded. I tried it several tanks full. I saw no difference and certainly not 100 miles more. I doubt that can be accomplished without some other mod or an error in calculation. If it were possible gasoline manufacturers would be touting it and the BO admin would be requiring it. I even ran 110 in it by mistake one time no difference

[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