Question about proper PSI on E rated tires

[Hkak45]

Hello,

I have toyo open country AT3 E rated LT265/70/17 and can't seem to figure out what the proper cold PSI should be for on road driving? I'm thinking 36 psi is ok but can't validate that answer.

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[Brian_B]

Chalk test

 

[GI_Jo_Nathan]

Chalk test

This.
There is no one answer. Too many variables.

 

[Fmuguira]

If you have vehicle weights as equipped or driven, then you should be able to do a calculation for proper psi …. If you purchased the tires from a knowledgeable tire store/person they should be able to help you on the calculation also.

Chalk test as mentioned is another way…. I ve heard interpreting the results correctly takes a little experience too… don’t personally know.

 

[dgorsett]

What everyone else said.

I also run 265/70x17 LRE, for over a year now. Started at 36 psi, seemed a little harsh, at 32 now seems very nice. I have noticed no abnormal wear. I think I'll run 32 for a while. 2dr non Sas BB.

 

[Hkak45]

Thank you all for the replies. I'll look into how to properly do the chalk test and go from there

 

[Deere503]

This is what I use on all my vehicles to “ballpark” what the tire will carry at what air pressure. The Goodyear Territories that come factory on a Sasquatch model will carry 2535 lbs at 35 psi. So 4 of those will carry 10140 lbs. So I weigh my vehicles at the local elevator (I know not everyone will have access to a free scale) by front axle and rear axle and come up with a ratio for the MINIMUM amount of air pressure needed to carry that weight. If you know how much weight (vehicle plus cargo) you’ll be carrying then you just put more air in to carry weight. I usually run 5-10 psi over this minimum to make sure I have enough and use the majority of the contact patch. Please realize this will make for a little cushier ride and it might feel a little sloppier on the road because of a softer sidewall. But it’s a trade off.

A prime example using this technique is on a HD pickup where the factory wants you to have 80 psi in the tires and when you’re not hauling a load you wear the center tread of the tires out before the outer treads.

 

[JohnnyBronco]

Label on door jam should say 35-36. Long trip highway 44-45 for best mpg (long as in 2100 miles )

 

[kodiakisland]

First, proper PSI does not matter if they are C, D, or E. PSI is specific to vehicle weight and tire size.
Start with a load rate table such as this: application_of_load_inflation_tables_20200723.pdf (toyotires.com) Adjust as needed. I tend to roll on the lighter side except on long interstate trips for better mpg.

According to the NTSB, you need 1.6X your actual vehicle weight for safe highway use. Find your tire size and go from there. The reason for the 1.6X is to account for shifts in weight for acceleration, deceleration, and cornering. So, if your actual weight is 4500lbs, your tires should add up to around 7000lbs.

The door sticker is only for GVWR and the specific size listed on the sticker.

 

[carrellslake]

I’ve been running 35” E load range Falken Wildpeak A/T3W tires for 10,000 miles at about 27 psi. I used FORScan to adjust the low psi warning to compensate for the lower pressure. It feels right on my Sasquatch 2 door and the tires still have almost no sag.

 

[Copperhorse73]

I have 37” Maxxis Razr load range E and 31 front 28 rear is what works for me.

 

[da_jokker]

Yeah thats going to be the issue with E rated, the sidewalls are so beefy you vehicle may not have enought weight to sag them.

Going too low on air pressure will build up heat in the tire which of course is not ideal if it is too much. Sag on a tire wears on the sidewalls.

Even the Goodyears C rated takes like -15 lbs of air before they start to sag and I'd never run these on the street at 20 psi.

You going to have to do the chalk test because of the stiffer sidewall, but I personally would not go lower than the low 30's

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