BFG MT KM2... pressure check?

So I got my first set of Mud Terrain KM2's and was surprised to see a max pressure of 80 PSI on the sidewall. The shop that installed them recommend I run 50 PSI which also seemed kind of high to me, coming for running 32 PSI All Terrains. I'm curious what other KM2 owners are running when on-road? Do you still air-down to say, 15 when off road, or is it something correspondingly higher?

 

I just put mine on today with 5in of snow on the ground. I left the shop on 25psi

 

I have had mine on for about 1300 miles and I can not figure out what to run in them. I havent had a chance to do the chalk test because of the winter snow here in Germany.

I was running 46 in mine and they made the truck vibrate a little as well they were slippery as hell on snow and ice.

I had them set at 32 before and it seemed like they were rubbing the shoulders off the tread. I dont know if this is from body roll (stock suspension) or if this is from me cornering to fast on the pavement.