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Monday, March 20, 2017

Am I reading Load & Inflation tables correctly?

Wayne M. asked

Tireman, Here is some information on my Toyo 265/75R22.5 LR-G tires. Can you confirm I am reading the tables correctly?
Toyo 265/75R22.5
PSI     70     75     80     85     90     95    100    105   110
Dual 3625 3705 3860 4040 4205 4410 4525 4685 4805(G)
Sing 3875 4070 4300 4440 4620 4805 4865 5150 5205(G)

Measured scale weights on each corner
RF: 4650        LF 4750
RR: 9000       LR 8250

Right side has Refer. There isn’t anything in the bays (not all the way through bays) that I could possibly switch around for even distribution so I have to go with the heavier weight.

I’m thinking 100 psi for the front.
What would my rears be with a fudge factor?

++++++++++++++++++++

First off , I have to thank you for providing the information on your specific tires and your actual tire loads for each end of your axles. I prefer data to guessing.

With 4,750# on the heavy end of the front axle we see that 95 psi can support 4,805 so that would be the MINIMUM Cold Inflation Pressure for your fronts (remember all tires on an axle should have the same CIP) and I suggest you add 10% (10 psi) cushion to get 105 psi CIP on the fronts.

The rears are dual, so looking at those inflations.  9,000 divided by 2 gives 4,500# per tire, with the 90 psi being the minimum inflation needed to support the measured load. Adding 10% or 9 psi gives us a suggested 99 psi. 100 is easier to remember and measure so lets go with 100 CIP on each of the 4 rear tires.

Comment: Please always adjust inflation up and avoid going down no matter how close the weights are.

##RVT786

1 comment:

  1. I could not find it, when buying new tires what is the oldest date to accept? They say it stars with date of sale, but when buyer looks at tire date he does not see invoice!
    New Michelin chart shows 80 psi as the lowest setting which is good for 3640lbs. My older chart shows 70psi as the lowest setting, good for 3440lbs.. my actual FL weight is 3200lbs. Similar for the duals.
    245/70r19.5
    If I extend the chart I should be able to use 60psi, based on weight.
    Do I go by the lowest setting on the new chart, even tho it will make the ride hard?
    Thank you

    ReplyDelete

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