These wheels use tires that inflate to an ideal pressure of 2.5 psi. (Automotive tires other other pneumatic tires inflate to 35 psi. or more.) These tires are so soft, they flatten soft sand and distribute their load over a wide surface. Other tires just dig ditches. These tires also conform to irregular terrain making rolling over rocks, branches, or other obstacles quite easy. The following video clearly shows how our wheels make easy work of rolling over soft sand.