I think this may be beat to death...

I have an 05 Lariat Supercrew 4X4, 5.4...

It came with LT275/65/18 Goodyears...I am now on my 4th set of tires...

I had 2 sets of Toyo Open Country At's, and now have BFG Rugged Terrain's...stock size LT 275/65/18...It seems that if I run the door tag pressure of 40 psi, they look flat (literally...rim is about an inch above the ground)...I am up to 60 psi, and they still look flat...the ride is much stiffer at 60...

I have seen the conversion formula for Toyo...but can't find anything on BFG...
I am assuming each manufacturer has their own air pressure formulas based on their designs...anyone seen supplemental info for BFG?

I was looking at a buddies new set of Toyo Open Country on his 3/4 ton Dodge, and they don't look flat like all of my past tires...I think he was at 60 psi...

 

Call BFG directly and ask them.. Get it from the horses mouth.

It's what I did when I purchased my 285/65/20's. They told me 45psi.

 

What load range are these tires? What is the Max pressure marked on the sidewall?