LT275/70R18 and LT285/60R20 Inflation Table

[SnoKing]

Both of these standard RAM tires follow the same industry standard inflation table. SNOKING

LT275/70R18 and LT285/60R20
PSI RATING
35 2070
40 2270
45 2470
50 2680
55 2840
60 3020
65 3195
70 3360
75 3530
80 3640

Source and other industry standard sizes. Scroll way down, LT's start on page 22.
https://toyotires2-1524598101.netdn...ication_of_Load_Inflation_Tables_20151020.pdf

 

[Alphonse]

Good data here

Thanks Snoking for posting this pdf.

This is a valuable document and and as you infer, it is a compilation of the the Tire and Rim Association data set (not Toyo proprietary). These are the minimum requirements that tires must meet per the TRA standards, whether it be Michelin, Firestone, Toyo, or XYZ company. This data is reasonably hard to find in a compilation like the attached and this appears to be the latest (2015) information. For example, I have called Michelin trying to get their compilation and they refused to give it to me acting as if it were proprietary. It is not and if you want it, you can buy it directly from the TRA but the book costs a couple of hundred bucks as I remember! The attached PDF is not all the TRA data but has it has a lot of the data that one might be looking for in regard to our trucks.

So thanks again for posting it. I have taken the time to tuck a copy away in my files on tires.

 

[SnoKing]

Blame it on Dogpatch, he sent me a PM looking for tire pressure charts I had posted earlier. SNOKING

 

[Dogpatch]

I'll take the blame LOL

So with my unloaded rear axle weight of 3615 lbs, does that mean I still have to run at 80 psi?
My front axle weight is 4975 lbs.

I saw somewhere they recommended normal running psi at 55 psi front and 75 psi rear.

I have a hard time wrapping my mind around this why rear should be higher. Other than when loaded.

 

[SnoKing]

I am running 48 in the rear and 58 in the from empty. The 48 in the rear accounts for casual day to day loads. For our trip South I have 60 in the front and 80 in the rear. I may let the rears down after hitting an Oregon scale house. I can not remember what the door jam says for the full 7K load on the rear axle, however 75 inflation would cover that. I think I will be around 6500 on the rear axle. They(Oregon) are nice in that they leave the scales on when unmanned, and have a readout on a pole past the scales, so you do not even have to get out of the truck. SNOKING

 

[Dogpatch]

Sheesh! I've gotta adjust my pressures. My truck rides like a "Buckin Bronc" right now.

 

[Alphonse]

Yeap, let the pressure down in the rear and you will be surprised to the effect regarding ride. I have gone from the 80 listed on the Tire and Load Placard to 60 in the rear for light load and it made a remarkable difference.

The only downside for that on the 2500 you get a low pressure warning pop up on the screen and an idiot light. There are are several posts here and on the other forum about that being curable with a dealer reset of the alarm point. I hope to get that done next year.

 

[SnoKing]

Yeap, let the pressure down in the rear and you will be surprised to the effect regarding ride. I have gone from the 80 listed on the Tire and Load Placard to 60 in the rear for light load and it made a remarkable difference.

The only downside for that on the 2500 you get a low pressure warning pop up on the screen and an idiot light. There are are several posts here and on the other forum about that being curable with a dealer reset of the alarm point. I hope to get that done next year.

Just another reason to buy a 3500!!!!

My 2001.5 came with 265/75R16 rated to 3415 and was placarded for 70 in the rear for match the 6K RGAWR. I will have to look again at the 2015 placard. SNOKING

 

[Alphonse]

Could be right, but it doesn't have coils.

 

[SnoKing]

Could be right, but it doesn't have coils.

That's good! SNOKING

 

[Cummins12V98]

Sheesh! I've gotta adjust my pressures. My truck rides like a "Buckin Bronc" right now.

Try 60 front 40-45 in the rear. Any less on the front you will have edge wear.

 

[photowrite]

I am running 48 in the rear and 58 in the from empty. The 48 in the rear accounts for casual day to day loads.

Yup, could not agree more about running much less than the maximum for much less than a maximum load.

For our trip South I have 60 in the front and 80 in the rear. I may let the rears down after hitting an Oregon scale house. I can not remember what the door jam says for the full 7K load on the rear axle, however 75 inflation would cover that. I think I will be around 6500 on the rear axle. They(Oregon) are nice in that they leave the scales on when unmanned, and have a readout on a pole past the scales, so you do not even have to get out of the truck.

It is great to know they leave the scales on in Oregon, I love to weigh my outfits but typically have to pay for the service.

 

[Cummins12V98]

Several DOT scales along I-5 are on also.