what 's the correct air pressure when doing it on sand, on highway, and on offroad.?

[Wisha Haddan H3]

I'm still experimenting with tire pressure myself, but this is what I've tried with the stock tires so far. On road, 40 psi was pretty stiff on denver's cracked pavement, but 35 rides much nicer. 25 psi gave me plenty of traction on dirt and gravel going up red cone, but 20 did much better on rocks during my last trip. I may try 18 psi next trip and see how it goes. Haven't run any sand yet.