I put a set of larger tired on my truck and wondered how it affected my odometor. I remembered that I had my GPS in the truck, so got it out and it was really amazing. I do not know how fast a handheld GPS will clock, but it has to be over 65mph. Anybody have an idea? And by the way, I gained 3 miles an hour at 30mph, 4 at 43mph, and 5 at 56mph. :eek: