I was wondering what pressure you guys run your ATV type tires at. my tire size is 21x11x8. On the Carlisle Power trac II's the sidewall states a maximum 5 PSI operating pressure and 15 PSI Seating pressure. These are 4ply soft v tread tires, but not the crazy Hard V you see on trenchers. the lower PSI gets me a better ride and traction, higher psi makes the tires bigger and mower will go a bit faster. Ideas?