Some down to 20 psi, some to 15 psi, some to 10 psi, some to 5 psi... see for yourself what works and what doens't.

When airing down, consider these:

• Increases the contact area of the tire, so more floatation
• Smoother ride
• Decreases the contact pressure since the vehicle weight will be spread over a larger area
• Easier to damage the sidewall
• Need compressor to air back up after the fun is over
• If pressure too low, risk of tire coming off the bead

hehehe