I'd go down to 20 psi. Any lower than that and you might risk de-beading the tire. If you want to get risky then you can try going down to 15, but I would highly suggest against going any lower than thatI have a 2022 Defender 110 with 19 inch rims and stock off-road tires. Are there any air down levels anyone can provide? Thanks.
The $35 or so Harbor Freight air compressor I have absolutely rips and I haven't had any issues with it. Fills up all of my 32s from 15-28 in like 12 mins total. For deflating just one of those valve core deflation things with a gauge is good.I’ve seen a variety of tables for this but the overall principle is to drop tire pressure 25% for washboard, 33% for slickrock, and up to 50% on sand.
If you run normal XL rated tires that have a max of 50PSI, these numbers make sense. But if you’re running a heavier C-E rated Light truck tire like I did for a while, I find that this guidance needs to be as a PERCENT OF YOUR ROAD MAX, not the tire maximum PSI that it’s capable of. So my tires can run at up to 80PSI. I found that pretty harsh so I run them at 50-60 (still figuring that out). And I’ve found that dropping to 40 smooths out the washboards and I’ve run them as low as 20 in soft sand. So your mileage will vary.
Since you're running factory tires, you can ignore all of that section above.
How to air down? I use an InDeflate. It’s fast and lets me drop two tires at once (fronts or rears) to the same pressure in < 1 min. Way better than fussing around trying to let air out of 4 tires with your fingernail or a small pressure gauge / bleeder.
For airing up, use good tools. If you buy a crappy $99 air compressor it will likely fail. Or it will take you 30 minutes to air up. I use an ARB dual compressor plugged into the InDeflate. That lets me inflate both tires (fronts or rears) simultaneously to the exact same pressure. All the air chucks are high quality so you can attach them and not fuss around.
I've generally followed the Tread Magazine guidance:
lower it by 25% for washboard, 33% on slickrock, 50% for sand driving. I've gone as low as 10 PSI in E-rated 80PSI capable Coopers to get unstuck from high-centering on a dune but immediately reinflated them back to 50% for the run out of the desert.
Vehicle: 2013 Land Rover LR4, 18" LR3 alloy wheels, LT265/60R18 Falken Wildpeak AT3W XL
Airing Down and Back Up the Right Way
The load index 109, on the right, is used with the load range to calculate optimum pressure. A reader, Christian, sent in this comment to my recent post The physics of tires and lifts : I have a related question that might warrant its own post. Is there a formula for fiwww.exploringoverland.comAiring down in Egypt My early four-wheel-drive experience was strictly trial and error, heavy on the error. A friend owned a beat-up mid-60s FJ40 shod with skinny Armstrong True Tracs and equipped with a Ramsey winch wrapped with a rusty steel cable. We took that thing everywhere, including trailswww.exploringoverland.comOne of the most frequent questions people ask me is, “What’s the the best thing I can do to improve my vehicle’s off-pavement performance?” Many of them seem distinctly disappointed when I answer, “Air down your tires.” I’m sure they’re hoping I’ll facilitate some expensive and impressive modificatiwww.exploringoverland.com
That Harbor Freight compressor has been through it and keeps on ticking. I'm sure there is better stuff out there, but it's pretty much the best one under $100. Project Farm on YouTube did a video about them and it came out on top. I like to balance cost and usability - I don't need the nicest stuff, and it gets prohibitively expensive really quickly.I think the key is focusing on reliability (will it work when you need it), durability (will it continue over time), output at high pressure (mfrs like to use CFM @0 PSI to trick you - what matters is CFM at 40+ PSI - how fast can it fill up near the end?), and duty cycle (how long can you run it before you have to turn it off to let it cool down?) Personally I would not trust a $35 compressor but that's the joy of 4WD'ing - there is no right way and it's up to each of us to find what works for us. I'm probably more in the "buy once, cry once" camp for critical safety items.
Choice of equipment aside, it sounds like V50 and I are pretty close on tire pressures and his suggestion to stay above 15psi. That would be a 70%-75% reduction from your 43/50 PSI road max and I can't fathom why you'd ever get there except in a recovery / max traxx / sand situation or something.
I definitely started with the 25/33 numbers and used my butt in the seat to judge it from there depending on the terrain.
Ultimately I like the message in the Tread Magazine and Hanson's articles which is...don't be lazy...air down and air up because that will improve your safety and effectiveness off road - no matter how you do it or what tools you use to make that happen.
Also, this is an oldie but a goodie if you haven't googled it and found it already: