correct tire pressue confused

It is counterintuitive, but LT tires (heavier duty tires than the euro metric or P metric sized tires) are supposed to run higher pressure than the light weight ones. It all comes down to load carrying capacity. Generally online you can find each manufacturers pressure/load number for each tire/size that they make. If you can't find the specifics, another google search will find generic tables for the LT vs P or Euro metric based on tire size. What the truck manufacturer wants you to do is pressurize your new tires to the level needed to match the maximum load they originally specified for their trucks at each wheel. My Tacoma is new - a 23. My door sticker recommends a tire pressure of 30 psi. If I look up Goodyear Wrangler tires in my stock size (P265/70/R16) in the pressure/load table I see that Toyota has recommended that the tires each be inflated to support roughly 2100 pounds. If I switched out my tires to new ones of the same size - but LT (e rated) tires - LT265/70/R16 the psi needed to support the same 2100 pounds at each wheel will be about 44 psi. This all sounds very complicated; but it really isn't once you find the tables and see what's going on.

In essence, LT tires have tougher and thicker sidewalls than P or euro metric tires. As such, if you load those tires up and drive fast, there is greater propensity for the heavy duty tires to generate too much heat in the sidewalls if they are allowed to flex as much as the P rated ones can. For our Tacomas, generally P metrics should be filled to somewhere in the low to mid 30s for highway driving; and LT metrics tires should be run in the mid-40s for highway driving (this all to make Toyota and tire lawyers happy). If your new tires are P metrics and they are replacing LT tires (which the door sticker seems to indicate because you have a Baja race ready tire) 48 psi is way too much.

Sorry for all the text; but this comes up all the time but never seems to be adequately explained.