With my grim reapers I started out with 14, then dropped to 12. This year I think I'll try 10 and see how I like it.
I usually take a compressor with me on the trail so I can re-inflate if necessary. With every brand of tire I've had I always had to play with pressure to see how I liked the feel and handling.
2010 Prowler XTZ 1000-
27" Grim Reaper Tires/Home Made Roof/Arctic Cat Mirror/Quadboss Folding Windshield w/ home made support bar/LED Tail-Brake lights//Venom 4000 lb Winch/Amsteel synthetic line/Home Made Doors/Custom Adjustable Seats/Custom Oh Crap bar for passenger/Tonneau Cover/Fat Max storage Box in bed
Tiger Tail Towing system