Just picked up some G/Y Wrangler Dura Tracs in 265/75/16s. The max cold psi is 50lbs and the G/Y tire store has 30lbs in them is this correct?

How do I determine what is the best pressure to use?

 

the TPMS usually goes off at saying it is too low when it drops below 35. I keep my tires at around 38 when driving on the streets.

 

well the norm for a tire is 32 psi it has the best mix of comfort, milage and wear however you are driving a truck not a car and most tires on light trucks should be around 40 psi for load comfort wear and milage, but i would think that the store only put in 30 (to low see ford's Explorer @ 27 psi and rolled over) to give you a nicer ride not realizing that air is in the tire to cool the tire and not act as a cushion/spring or their guy just didn`t think or know that a car is lighter than a truck and the truck has to have more air for the increased wieght