PSI while driving in muddy areas

Hello Forum,

I've read that it's good to run 12-15 PSI while driving in sand but how much PSI is good when driving in light to muddy trails? I have BFG A/T 265/75R16 "E"

Also, I've had this compressor for about 3 months. My neighbor traded in his truck & gave it to me. He used the can of Fix-A-Flat that it came with but he never used the actual compressor. He said that it was included in the purchase of his truck (GMC Sierra 1500) when he bought it new in '09. I would like to find out the specs on this compressor. It has NO name & NO model #. Only info is a Serial #011200019653 & it's "Made in China" sticker

I tested the compressor by first deflating all 4 tires to 12 PSI.
It averaged under 5 minutes to air each of my tires up from 12 to 32 PSI & I did all four without giving the compressor a break. It was barely warm. Not bad for what I assume is a cheap compressor.

My tires at 12 PSI:





The compressor:





Thanks