i took my nissan hardbody with a 2.4L on the dunes in oklahoma. at first we were driving in 4HI, but moved to 2HI when it was apparent we werent gonna get stuck. i think we were cruising along at like 40ish miles per hour, liquid courage. haha, didnt even air down the tires (goodyear MTR's). with a quad in the abck it would be a lil different though. like wallrat said, speed is KEY when going uphill.