The vehicle door recommendations are based on the vehicle weight.

Just as the previous poster said the door did not know what tires you have on the truck, neither do the tires know what the truck they are mounted on weighs.

If you are running the tire size recommended by the vehicle manufacturer, then their recommended inflation numbers will give you the best ride and reasonable tire life. If you want to sacrifice a bit of the smooth ride, you can boost the inflation a bit and get better gas millage.

If you want the absolute best gas millage, but do not care about accelerated wear and rough riding, then run the tires at their maximum safe pressure.

Tom