tire size

[MarineHawk]

Originally posted by PhilD:
The only problem with measuring the circumference, is that it does not take into account that the tire isn't round when on the vehicle, the bottom section is somewhat flattened by the weight of the vehicle. If there was no load on the tire, then the circumference method would be accurate, but with a load on it, it will not be correct.

Yes, and by measuring the circ when driven, it is the circumpherence under load.