Tire pressures vs chart

[tarnold]

On CAT scales, my e350 loaded is 10,380. 3280 front, 7100 rear. Door sticker says 65f/55r. Duals on rear. Per Michelin chart a 225/75/16 s/b 55 rear as is door sticker for my weight. BUT the chart for single axel, 2 tires is 40 psi. For my front weight of 3280. That can’t be right. What am I miss reading?

[azdryheat]

Cummins12V98 wrote:

IAMICHABOD wrote:

Cummins12V98 wrote:
I use the charts and add 5psi for rears and 10psi for fonts.

Why do that? :?WAG would get the same results......

I have very specific reasons for doing so with several sets of tires making it to 100k and beyond.

Thanks for your constructive post!

What would be some of your specific reasons?

[Cummins12V98]

IAMICHABOD wrote:

Cummins12V98 wrote:
I use the charts and add 5psi for rears and 10psi for fonts.

Why do that? :?WAG would get the same results......

I have very specific reasons for doing so with several sets of tires making it to 100k and beyond.

Thanks for your constructive post!

[IAMICHABOD]

Cummins12V98 wrote:
I use the charts and add 5psi for rears and 10psi for fonts.

Why do that? :?WAG would get the same results......

[DrewE]

The door sticker usually assumes the maximum rated load for each axle (i.e. the GAWR). Ford doesn't know how you or the vehicle outfitter will be loading their chassis. If your front axle is lighter than the GAWR, then you can safely use a lower pressure as per the tire manufacturer's recommendations.

[Cummins12V98]

I use the charts and add 5psi for rears and 10psi for fonts.

[naturist]

Wrong chart.

Stick to the one specific for your truck and tires. This ain’t a one-size-fits-all situation.