|"I told you we should have lowered the tyre pressure some more."|
Hard-core enthusiasts, on the other hand, want maximum traction and will run the lowest pressure they can get away with. They will normally run tubes and maybe beadlockers to achieve this. I've never had beadlockers, but used to run my tubed tyres as low as 6psi on the Land Rover when conditions warranted it. The grip was amazing. Usually, I found 16-17psi satisfactory for a rutted and muddy track. Many drivers, myself included, also like to drop pressure for off-road comfort. Rutted tracks can give a jarring ride at street pressures; going down to about 24 is wonderfully smoothing.
Dropping pressure for sand driving is common, but only once or twice have I needed to go really low, like below 12psi. Running in the 20-24psi range usually does the trick and often it's not necessary to go anywhere near as low. However, there's more to good sand driving technique than just losing air.