Toyo ATIII tire pressure

I was doing some research on 315/70/17s in C load - came across the Toyo Open Country AT III and found their max PSI is 35..? Seems low.. Those who have these in this size/load, what PSI are you running? Thanks!

 

Not unusual for a C load tire.
Email Toyo and they will tell you what to run.

 

35 is in the ballpark for C load. I would think the sweet spot would be between 35-39 for C load. But some of that can depend on your trucks weight, load, how it is rigged out.

it is easy to find out the correct pressure for non stock tires by doing a chalk test.

https://www.youtube.com/watch?v=W0qL20nBNRI

 

The chalk test does not work for tires with crowned treads which a number or hybrid tires are starting to do.
Not sure if the ATIII is crowned or not.

The far easiest thing to do is just email the tire manufacturer.

To the OP Toyo lists MAX pressure as 50 psi for that size on their website not 35.

 

I disagree. A chalk test is a great tool and will get you within a few pounds of correct pressure for radial tires. Then you just go up or down a few psi and see what feels best based on your truck and driving.

I always install larger tires on a 4WD. I am not a young man so have completed this process on probably 20 different 4wd vehicles. Tire manufacture responses on air pressure are pretty much worthless. I have had responses of use the sticker on the door (completely wrong when moving from SL to E or C load tires) and I have had the same manufacturer tell me greatly varied pressure to run...one employee told me one pressure, another employee told me something completely different-same truck and tire size.

OP, check the wheel and tire section here. There is a thread in there, maybe a sticky, about how to determine air pressure when moving from standard load tires to LT type tires.

 

Here it is
https://www.tundras.com/threads/how-to-determine-your-new-air-pressure-with-lt-tires.56860/

 

Then you are unfamiliar with tires that use a crowned tread. In most cases the chalk test works but if the tread is crowned the chalk test will not work.

Here is a video explaining it. A whole lot easier to link the video than type it out.
https://youtu.be/iGB0f9qn8-o

 

All tires have a crown, but enough on that. OP check the link above and use that chart to help you determine the psi. Drive it some, maybe adjust it up or down a few psi until you find what works best for your truck, weights and driving style.

 

I have always been told that you should drop your pressure until you have a full contact patch for best tire wear. You can add more PSI if you want a firmer ride, but you will just be accelerating tire wear in the middle of the tire tread since you are not using the full footprint. And I think that we can all agree about under inflating. Of course there are plenty of people that keep their tires over inflated when empty because they tow or haul often.

 

Copy, I failed to state in the original post that I found that max PSI on Discount Tire’s site.

 

35psi seems supper light for a truck tire.

 

Just checked Toyo's site and I think that Discount Tire has the wrong information. Would not be the first time, I found quite a bit of false info when researching my current setup.

 

they made a mistake, max pressure is not 35lbs for sure.

 

Yeah, Toyo has them listed as a D not a C2. I have never seen a D rating with 35 PSI max.

 

And another oddball thing- Crewmaxlmt is correct- toyo website shows that size as D rated. but I checked Tirerack and discount tire and the only ToyoAT3 in that size is showing as E load, details here https://www.discounttire.com/buy-tires/toyo-tire-open-country-a-t-iii/p/88622

 

Thanks for all the responses so far. I’ve run multiple sets of larger tires and tracking on how to set proper PSI, chalk test, etc - this just struck me as odd at 35 PSI, seemed super low and wanted to ensure I wasn’t missing something. The reason I started looking at these is because I’m currently on some E rated 34’s and it’s a stiff ride. We need more C load options!