Has anyone tried this tire?

[Alex702]

I have a question about tire pressure with the KO3s or tires that inflate up to 80 psi. I noticed that people are running 60 PSI as the norm versus the 48 from pirelli. Which is understandable. My question is when you're off-roading rivian recommends airing down to 30 PSI. Would that change with a ko3? What's the minimum tire pressure we can run? Should it be a higher PSI or a lower PSI? Or is 30 PSI the norm regardless of the tire? Carcass

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[mikehmb]

I have a question about tire pressure with the KO3s or tires that inflate up to 80 psi. I noticed that people are running 60 PSI as the norm versus the 48 from pirelli. Which is understandable. My question is when you're off-roading rivian recommends airing down to 30 PSI. Would that change with a ko3? What's the minimum tire pressure we can run? Should it be a higher PSI or a lower PSI? Or is 30 PSI the norm regardless of the tire? Carcass

The KO3 sidewall is considerably beefier than the OE Pirelli.

One other consideration is the wheel bead. Beadlockers are a thing because people want to run super low pressures in very gnarly environments.

 

[ksurfier]

See Toyo 275/65 load inflation table below (bottom), in contrast, a non-LT tire will reach higher loads at lower pressures:
Example: P275/60R20

PSI	116 Load​	GVWR
20 -likely minimum for sand only low speed (25 PSI if fully loaded)
22​	1830​	7320​
24​	1982​	7928​
26​	2116​	8464​
28​	2216​	8864​
30​	2392​	9568​
32​	2491​	9964​
34​	2619​	10476​
36​	2756​	11024​

For non-LT, looks like need a minimum of ~25 psi for offroad (prob. go a little lower if needed). An LT reaches a similar load at around 33 PSI. If fully loaded, would likely need at least 30 PSI for non-LT and at least 45 PSI for LT tire.

Non-LT	LT (add 5 psi if loaded)	Type | Contact Patch (est.)
48​	53​	Highway | 6.3" x 6.3"
42​	45​	Dirt roads | 6.8" x 6.8"
38​	43​	Crawling/rocky | 7" x 7"
34​	40​	More difficult trails/slippery | 7.4" x 7.4"
30​	35​	Trail/washboard | 7.9" x 7.9"
26​	30​	Sand | 8.5" x 8.5"

Can usually look at the tire for signs of being too low (rim should drop no more than 25% from max height, for example if rim was ~6.5" above the ground then when aired down it should be at least ~5" above ground)...at the high end, doesn't seem like you'd want to go much above 55 psi (LT) to keep the contact patch at the correct size, have heard there's no difference in MPK between 55 and 65 psi anyhow...

Here's a tire load inflation table for a Toyo LT275/65R20:

www.toyotires.com/media/pxcjubjs/application_of_load_inflation_tables_20200723.pdf

Toyo (LT)​	LT275/65​	GVWR​
30 -likely minimum for sand only low speed (35 PSI if fully loaded)​	1880​	7520​
35​	2080​	8320​
38​	2180​	8720​
40​	2280​	9120​
45​	2475​	9900​
50​	2680​	10720​
52.5​	2765​	11060​
55​	2850​	11400​
60​	3030​	12120​
65​	3195​	12780​
70​	3375​	13500​
75​	3540​	14160​
80​	3750​	15000​

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