I remember my first trip to Oceano Dunes, (back then we all called it Pismo Dunes)... my first time in sand, an old timer gave me simple advice "You want a good pooch in your tires " which is a bulge in your sidewall. Typically without beadlocks I start around 15-18psi for sand and adjust as needed. All depends on how heavy the rig is, size of tire, how stiff your sidewalls are, and how hard you plan to push your rig. Have fun, and bring a tow strap or kinetic rope...you never know, I typically end up pulling out 6-8 people a day when I'm out on the dunes. Enjoy! -Erika