here, this is how I found out: https://tiresize.com/pressure-calculator/ factory is P225/75/15 26 psi and SL load range (102)

mine says that max load is at 48 psi, but I wouldn't run it with a 6 play tire. I am putting a 3.3L V6 in it and I will be towing a small trailer from time to time, it weighs about 2000 lbs with the rzr on it, my tires are 104 load range. so it said that 39 is best for daily, and ill air the rear up to 47 or 48 when I am pulling the rzr behind it.

the rzr is a side by side atv: a 4 wheeler with bucket seats and fully independent suspension and a steering wheel and pedals.