[classic_erik]

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Humor me. I’ve been researching new cold PSIs for my aftermarket wheel setup. Hoping to clear up a little confusion.

So my OE tires are “A” in this photo. When I convert to my new sizing on the XL load tables I come up with the new recommended pressure of 39/40. I’ll use this on my new tires.

Now here comes my confusion. When I start with the optional OE “B” sizing, the converted new recommended pressure is 33/40ish (I can’t actually convert the rear properly since the load charts end at 42 PSI, but this is close I guess).

Why would the front tire new PSI be so different in scenarios A vs B? If they are both OE recommendations why does the different starting point produce such varying results? The vehicle is the same regardless of the original wheel and tire. I’m converting to the same new tire specs so this is throwing me off.

New tire sizing:

Front 285/40/22 110Y
Rear 325/35/22 114Y

[jadatis]

I can make you pressure/loadcapacity lists.
Normally I make them for max reserve, at wich comfort and grip is still acceptable.
Fir that I give 90% of calculated axleload and max speed 160 kmph/99mph.

Thinking of 110, 113 and 114 loadindex, so new tires are covered, and OEM A anld between A and B.

All are XL, so maxload AT 42 psi, but my list gives upto 51 psi, your maxcold.

Difference between 42 psi referencepressure and 51 maxcold is used to highen up the 42 psi for higher speed, with system depending on speedcode, but I use a system of lower loadindex for higher speed, looked off from LT and trucktires.

Then you only have to determine the axleloads 99% accurate, the most tricky part, and your responsibility.
But you also can look back the advice pressure of 113 loadindex ( A) for what loadcapacity it gives, and then for front in 110 LI look back that loadcapacity for the pressure. Same for rear 114 LI.

But to make that list, I want to know how you want it.
Kg or LBS
PSI or Bar
Your maximum used speed ( and wont go over for even a minute)
And if you have other idea about the reserves.

[classic_erik]

Sorry man not really following you here.

Anybody?

[classic_erik]

Bueller? 🙏🏼