Safe tire pressure when airing down

I am running stock size 265/70/17 SL rated Ridge Grapplers on stock 17x7.5 ORP wheels. When airing down for sandy beaches or light trails with loose soil, what would be a safe pressure to air down to? Thanks!

 

I won't go below 15 psi. Some here are more aggressive, but getting a bead back on is no fun. I've only reseated a regular tire, which was bad enough. An AT tire is a lot harder.

 

For sand you can go down to as little as 6 psi. Usually the ground clearance tradeoff becomes too severe. If you went this low rock crawling you'd most likely debead a tire without beadlock wheels. Some sand dune ORV parks like Silver Lake requires airing down to 15 psi or lower.



If you have a good air pump, you can seat a tire bead with a ratchet strap around the tire without using starter fluid or non-chlorinated brake cleaner.

Some tires like the Cooper STMaxx likes to collect debris in the bead area when aired down. Seen it with 3 trucks in my off-road club. It's related to the tire mold geometry in the bead area. I don't know if Ridge Grapplers have this quirk or not. The tires I've run (GY Duratrac, Kenda Klever RT) don't seem to have this issue.

 

OK, appreciate the input so far. I do not want to get into any situations where I pop the bead and have to reseat the tire.

 

I am a 15psi'er as well.

 

For me its very dependent on the trail, anywhere from 15psi to 25psi. On a beach i would go lower, but I like the woods.

 

For light trails I'd say it's up to you. I hit the easiest trails at a nearby off-road park at street pressure out of curiosity and it was still softer than the ol' crossover at 22-25ish psi. Footprint/grip/rocks wasn't a concern so it would've been a question of comfort.

Something bumpier, rockier I'd start somewhere in the 20's and see how it goes.

 

For me
18-20 psi is typically enough to soften the ride up and let the tire deform over obstacles.

Wouldn't go lower than 15 unless I was in snow or sand and really needed that extra traction.



18PSI 285/70/17 on a 8.5" wheel:

 

That's what I do (stock tire size)
20-23 dirt roads
18-20 light off roading
17-18 crawling (nothing too crazy)
15 in sand or really struggles and need to get over an obstacle (rare that I have to go that low though)

I personally wouldnt go any lower without beadlocks

 

One air pressure in sand does not necessarily fit all. With over 50+ years driving in deep soft sand around Cape Hatteras, here is a general rule that works for most stock radials in sand.


General rule is with vehicle loaded like it will be on the sand, including people, and vehicle on level pavement and tire pressure at recommended cold street pressure, measure the height from pavement to edge of rim. Then lower pressure until the height is ¾ of street pressure height. For my T4R this ranges from 18-20 psi. Recommended cold street pressure being 32 psi. Again it depends on load.

This gives the optimum flat footprint. Going much below that adds little in traction and makes it much more likely to break a bead.

I learned this from an old desert rat out west. It has done well for me.