Low air pressure harms tires?

[Smoking Denali]

I air down my 20" tires to 20lbs.  on beach.. Am I killing sidewalls?

[CamGTP]

On a beach at slow speeds it shouldn't be doing much to the tires at all. The sand is soft so it's not as hard on the tires like pavement is.

[Rygrego]

Airing down is the only way you will keep from getting stuck. I would suggest 10lbs as long as you air up the second you're back on solid ground. And you will not damage your tires at all.

 

[BlaineBug]

Only at speed when tires head up most and/or if carrying a heavy load will low pressure hurt them.  Or maybe if they are stored in one position for a lengthy period of time as well.  Airing down for off road conditions has been a tactic since the beginning of pneumatic tires.

[Pacfanweb]

Not at the beach, no.   Won't hurt, because you're going slow. 

It's terrible for them to run on pavement at speed with low pressure though.  Lots more friction and it'll harm them eventually. 

 

Not to mention the extra strain on the truck with all that friction and the bad gas mileage it'll cause. 

So air down, then right back up when you get off the beach.