Tire pressure ??

skyhighZJ

skyhighZJ

Gov retirement < needs to live
Joined
May 31, 2012
Location
Aberdeen, NC.
Bought new shoes for the dually. 35x12.50x17 Toyo ATII Load Range E 121r. The tire says max load 3195 LBS @ 65 psi cold. This seems low but I don’t want to over inflate them. The tires I’m taking off are max 80 psi. Getting ready to tow my toy hauler from Louisiana to NC and don’t want any tire issues. What say you?
 
The E load rating has nothing to do with 80 psi, except that many common tire sizes are specified for max rated load at 80psi at E load rating. There are a lot of sizes that are specified for max rated load at 65psi at E load, which is probably the second most common pressure. All of these things are specifications set by the TRA (Tire and Rim Association) for each tire size, and if you look up the 35x12.5R17 size in the TRA tables, you should find that 65psi and 3195lb is listed there for E-load (Toyo doesn't set those numbers).

What I'm saying is that the max pressure has nothing to do with the tires being from Toyo, and everything to do with what tire size they are, and that they don't have to be 80 psi just because they're E load rated.
 
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How balloony do they look on dually wheels? Assuming the factory wheel are like 17x6 or 17x7.
 
What they said above. Inflate them up to Max psi in proportion to the weight they're carrying and go. Don't exceed the Max psi on the sidewall.

Worst case is if the truck has tpms and the rears are programmed to throw a light below 80. May need the system reprogrammed for the lower pressure.
 
Tim C said:
What they said above. Inflate them up to Max psi in proportion to the weight they're carrying and go. Don't exceed the Max psi on the sidewall.

Worst case is if the truck has tpms and the rears are programmed to throw a light below 80. May need the system reprogrammed for the lower pressure.
Click to expand...
No tpms on this
 
Croatan_Kid said:
How balloony do they look on dually wheels? Assuming the factory wheel are like 17x6 or 17x7.
Click to expand...
261BC55D-4748-4D9B-88E8-299046899908.jpeg
3A036619-47A8-44A8-BEC0-F45FBF871036.jpeg
B3427CF3-A809-4187-89E8-5C1BEE7ACC5A.jpeg
 
While we're on topic, there is also a max load rating de-rate for dual instead of single. I had to look the actual number up (it's 9%), but it's because of road crown.

So that 3195 lb rated load at 65psi is actually 2908 lbs per tire in the rear.
 
Those don't look bad at all! How's the spacing between the drives?
 
I've got 2" Stahl spacers. Same company, but mine are steel. They make some nice stuff.
 
On the same lines. How do you find inflation pressure of up sized tires? You don’t want max pressure bc it will convex the tires and get center wear and a bad ride. Cant do door inflation bc they will be under inflated. What is one to do?
 
Side walk chalk across the tread. Drive a little. You want to the chalk to wear off evenly across tire. On the fronts you want everything to wear even across except the outer .5”. This makes up for the wear while turning.

I do this for every set except I just drive in my shop yard through the dirt/gravel/screenings/sand, and look at the dust on the tread.
 
Futbalfantic said:
On the same lines. How do you find inflation pressure of up sized tires? You don’t want max pressure bc it will convex the tires and get center wear and a bad ride. Cant do door inflation bc they will be under inflated. What is one to do?
Click to expand...
Basically I take the pressure at Max load and proportion it to the actual load, plus a little bit for safety. So a tire rated for 3000lbs at 60psi, on a vehicle with 1500lbs on each tire, proportionally it should be about 30psi. I'd start at 35psi and see how much the sidewall was deflecting and how it drove.
 
Mac5005 said:
Side walk chalk across the tread. Drive a little. You want to the chalk to wear off evenly across tire. On the fronts you want everything to wear even across except the outer .5”. This makes up for the wear while turning.

I do this for every set except I just drive in my shop yard through the dirt/gravel/screenings/sand, and look at the dust on the tread.
Click to expand...
this!! But then adjust if you run loaded - preferably repeat the process. Should end up close to proportional based on weight unloaded @what you determine && Max weight @Max pressure
 
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