Is 40 psi too high for truck tires?
In most of these cases, 40 psi should be more than enough, and since most modern tire designs will allow up to 44 psi (in some cases more) this is not a problem. If you have a heavily loaded vehicle, up to 44 or even higher is ok if the tire allows it, but this is a little high for most vehicles. They overinlate them at the plant to make sure that the tires seat on the rim properly. The dealer should have checked the pressure and adjusted it to the manufacturer’s recommended 39 psi. If you have a discount tire (and some other tire dealers) near you, they will do a free tire pressure check and adjustment.