Tire pressure recommendations needed

[WhiffySpark]

Diesel or gas? Are these oversized for the rims? I'm running 22.5" 10 lug on my dually. They are semi tires. The rating on the sidewall is way different on a 1 ton truck than a semi. Diesels are a lot heavier in the front than a gas. From your pic they are under inflated.

If it's wearing like that on both sides.

 

[whitetailhntr]

They look like that all the way around the truck. There at 40psi

 

[whitetailhntr]

I would think its over pressure since its pushing up the middle so much

 

[Robbie13]

I would think its over pressure since its pushing up the middle so much

Yes, my bad. Over. Add some more to it. Roll with that for a while. Also the chalk thing works.

 

[whitetailhntr]

Yes, my bad. Over. Add some more to it. Roll with that for a while. Also the chalk thing works.

Im going to try and take 3psi out of each and see how that looks. After reading the attached link from above it makes sense that a bigger tire requires less air pressure which before i was thinking bigger meant more air pressure. Great info.

 

[whitetailhntr]

I could try to explain a lot of stuff, but I found a great link on the first page of searching for you, aka "spoon feeding." If going with stock size and weight rating tires, I follow the door placard/owner manual. If going with a size and/or weight rating other than stock, I either use the scale method or the chalk method as outlined in the link. Read through the link a few times and determine what method will be the best fit for you and the amount of time you want to invest in getting a proper air pressure for your situation. Check it out:



http://www.4wheelparts.com/tire-wheel-package-guide/tire-pressure-checker.aspx



Good luck! Enjoy your new wheels and tires!

Great info thanks

 

[pepi]

Tip # 1..... check the pressure often, every oil change is a good time. Tip #2 do it your self....

 

[Thezapper]

Do you guys remember the Ford Exploders? Firestone tires had one recommended psi range and the dealer / door sticker deliberately lowered that to improve the ride quality and cost them dearly...I say it's a judgement call, the Chalk test sounds great a kick on the sidewall works too....

 

[whitetailhntr]

With the chaulk method how much chaulk should remain on the edges after the test?

 

[whitetailhntr]

Mine are 3/4 inch clean on each side

 

[elba]

On a Lockheed L-1011 we put 210 PSI in the mains and 180 PSI in the nose tires !

 

[600SL]

I still don't understand what the vehicle mfg. has to do with the tire specs from the tire mfg? To me this is akin to wanting to paint a vehicle using Sherwin Williams paint product and I have to ask Gen. Motors what type and amount of reducer to use. I'm not doubting the directive to go by the stated psi on the door jamb.....I fail to see the connection.

Tire pressure has to do primarily with the weight of the car and size of the tire. Therefor the auto manufacture is best suited to set the tire pressure. If you deviate in size from the tires that came with the car you are on your own.

 

[Denwood]

Tire inflation recommendations correlate very closely with GVWR (often different from front to back) and the the load tables for a given tire.

To establish inflation correctly, you need to know the specs for the OEM tire and your door sticker values. Calculate inflation pressure using the following formula:

[Original Tires Max Load Rating] * [Sticker's
Recommended P.S.I.] / [Original Tires Max P.S.I.] *
[New Tires Max P.S.I.] / [New Tires Max Load Rating]

If for example your OEM tire is load rated C, and you purchase load rated D tires (exact same size) your inflation pressures will drop. On the autoX track we set inflation based on temperature, chalk markings, and desired handling bias. For example, inflation of the rear tires beyond the "formula" numbers will generally increase oversteer. If you arbitrarily set inflation pressures, you run the risk of tire wear problems and handling bias that the car manufacturer did not intend.

If you're interested in the tech side of this discussion, this is my goto reference: http://www.toyotires.ca/sites/default/files/loadinflationtable.pdf

 

[whitetailhntr]

Broken link

 

[Denwood]

Sorry about that..fixed: http://www.toyotires.ca/sites/default/files/loadinflationtable.pdf

 

[whitetailhntr]

50psi for my vehicle