For those of you with Edge Evo's, you know that you can correct your tire size when programming. The Edge manual gives you a formula to do so. Follow the link below for a tire size calculator. Just type in your tire size and it will give you the circumference in millimeters.

I found this easier than using the formula in the Edge manual.

http://www.1010tires.com/TireSizeCalculator.asp

 

I still prefer to measure mine on the driveway. I think the weight of the vehicle, air pressure, and type of tire will make a difference in the size. No two tire manufactor will be exactly the same. I remember measuring old bias ply tires and getting at least 1/2 inch difference. I would put the tallest tires on the rear.

If I have time tomorrow I will check my theory. I just put a new set of Goodyears on my worktruck. Same size as the Mich on my Supercrew with the EDGE. 265/70/17.

 

I never looked at it that way. Definitely makes sense though. I think maybe I will have to try this also.

 

I used to be trained in the use of VASCAR. We always had to make sure the air pressure was right on prior to calibration each day. We always used the same brand of tire, so I never had a chance to check the difference with the VASCAR.

 

This would make you an officer of the law?If so thanks and Good Luck,thats a job I just could not do.I don't have the self control needed now a days.