Ok. Just updated the Flashpaq online. Thanks pickles. I want to set the tire size when I install. They measure by increments of 1/4 and say to round up. I have 33X12.50 Duratrac's and their specs online are 32.8 outside diameter. I measured like they recommend, using a tape measure from the ground up to the bottom of a ruler that sits on the top of the tire. I measured 31 3/8". What happened to my 33's? I guess I will be 31 1/2 based on their recommendations.