What PSI do you run with KO2 275/65/18?

[Teeter]

I just got back from the beach where I had dropped the PSI down to 20 to run on sand.

Before letting the air out, I checked the pressure and was surprised to see it sitting at about 65psi (I had not checked them since I had the shop put them on a few months back). My 2013 Tacoma runs at about 33 psi, hence my surprise with the LC.

Anywho, I topped them back off to 60 when I got back to pavement but can’t seem to find a good guide. Tire says max 80.

Just looking for some guidance for no-load daily driving.

thanks!

 

[MJK]

Sounds like E-rated KO2s. I run those on my 7700lb 3/4 ton at 68PSI.

I don't run e-rated on the 100, but backing it off some due to the reduced weight sounds about right. I daily 34PSI on Michelin LTXs on the 100.

I pick tire pressures with a chalk test (trucks) or an IR gun (sports cars). The goal of either is to get even wear across the tire.

 

[JunkCrzr89]

32-35 psi on road, 40-45 towing on road, 15-18 off road.

Tire shops like Discount Tire, etc. are notorious for overfilling tires, often to the max psi rating.

 

[AlpineAccess]

Easy way to know for sure is to chalk test the tires to find the right PSI range. Takes about 5 minutes.

You'll be able to get within +/- 5 lbs, and then it's personal preference if you pick the high or low range of it.

 

[AlpineAccess]

This is the best tutorial I have found on chalk testing btw.

What Psi should I run - Do a "Chalk Test" to determine

*CHALK TEST: Instructions: -In the morning, before sun beats down on your tires and before you drive the truck- Fill the tires to a good starting pressure. If you are unsure what pressure to start with then subtract 10 percent from the manufacturer's maximum inflation pressure on the...

www.jlwranglerforums.com

 

[Pucker5]

When in bought mine they were set at like 38. I bumped to 44 then I went to 48 where I am today. I want to maximize the life of the tires so I run em with more air. That logic worked well with the og ko’s. Could run them at 55+ on highway and get 70k miles on em. I know the new compound won’t net even close but I think the high psi logic still applies

Edit: just checked and I’m at 44

 

[JunkCrzr89]

When in bought mine they were set at like 38. I bumped to 44 then I went to 48 where I am today. I want to maximize the life of the tires so I run em with more air. That logic worked well with the og ko’s. Could run them at 55+ on highway and get 70k miles on em. I know the new compound won’t net even close but I think the high psi logic still applies

Burn through the center tread...

 

[AlpineAccess]

It's almost as if there was a way to know what pressure to run.

Like...a test or something that you can do to know for sure...

 

[suprarx7nut]

Mine are slightly larger diameter (275/70/18), but I have settled on ~33 psi for road driving and 20 for trails worth airing down. Now that I've got on-board air I'll push that aired down limit closer to 15.

Tire shops seem to aim for 45+ on those E-rated KO2s, but that seems unnecessarily harsh in a 100.

 

[Teeter]

Thanks for the info, I’ll dial it down a bit.

 

[Kabanstva]

Did KO2s ever come C-rated in a 285/75/R16? Or only E-rated?

 

[george_tlc]

You need to measure tyre pressure when they are cold. Op: if you measured 65psi 'before' hitting the sand, the tyres were likely hot from running on pavement.

And, NEVER EVER trust the monkeys that work at tyre places to do the job right - at least check what they've done, including the torque on each and every lug nut. It's your (and your family's) life - not theirs at risk...

cheers,
george.

 

[tonyholland00]

Mine are slightly larger diameter (275/70/18), but I have settled on ~33 psi for road driving and 20 for trails worth airing down. Now that I've got on-board air I'll push that aired down limit closer to 15.

Tire shops seem to aim for 45+ on those E-rated KO2s, but that seems unnecessarily harsh in a 100.

I just had same gifted installed today on 2020 he, discount tire had air pressure around 48. Ride like a stiff board. Dropped to 35 and now much better.

 

[thibaut]

The new BF AT KO2 have reinforced sidewalls and I find them great at 2.2 bar / 31 psi (cold pressure) for road usage.
Beyond 35 psi you really start to lose comfort.

 

[SlowBuild]

I think there’s supposed to be a 5% pressure change hot:cold. Measure cold, drive until hot, measure again. Adjust air as necessary to get to 5% change.

The chalk test roughly gets you even wear but I’m pretty sure tire manufacturers spec air pressures to optimize sidewall deformation (not tread wear) as the tire spins and heats up the air inside. Not everyone has an IR gun to measure the temp change between cold and hot but the corresponding increase in pressure is easy to check and adjust.

Disclaimer: I’m always too lazy to use any of these methods, I always just go by feel unless I get poor wear, which is almost never an issue.