MFL. Pretty sure the OPs tires are not LT with only a 113 load index, but then again I’m not a wannabe tire engineer. 
However I do know enough to know that most, many, all? Probably not all, light duty P/XL tires achieve max rated capacity before max psi rating. 
But ICBW , and always welcome some new knowledge if I’m wrong. 
Just doing my due diligence to keep all the newbies from walking away thinking they need E load tires and a dually as soon as they even think about putting a trailer on the back of a truck.