Heh, I actually tested my speedo yesterday. I was about 4-5mph off with worn 30" tires. I used a GPS with WAAS. So, when my speedo reads 75, I'm actually going 70. However, mine is an SR, so its supposed to have 31's.

[color:"red"]1992 Monty SR, bouncy seat, custom steering wheel, torsion lift, BFG 31" AT, luxurious wood interior. 230k. [/color]
"Give the bully another point."