I had a dually with the old standard 16" wheels. I aired down at pismo beach and it did great, it even went down the sand highway. Get this, it was a 2wd with a 5"front 8"rear drop.
Both front tires were destroyed very soon after. One I noticed and pulled over and changed as it was coming apart, the steel belt was showing and much of the tread was delaminating. The second one went soon after in a violent blow out. I would never again air down that type of tire.