Tire pressure nonsense

[wolftimj]

I just switched out the 255-70-18 KO2s that I got with my rig for 285/75-17 HD-Terrains on AO XT rims. Got rubber at Costco and had them swap the original TPMS into the new tires in same position. Worked well. The nonsense part, maybe; they said since they are E load range while originals were D so I needed to run higher pressures. I cannot find anything online to confirm this, everything I find says to run at the same 36psi I had before. Anyone think Costco is right?

 

[trobex]

I just switched out the 255-70-18 KO2s that I got with my rig for 285/75-17 HD-Terrains on AO XT rims. Got rubber at Costco and had them swap the original TPMS into the new tires in same position. Worked well. The nonsense part, maybe; they said since they are E load range while originals were D so I needed to run higher pressures. I cannot find anything online to confirm this, everything I find says to run at the same 36psi I had before. Anyone think Costco is right?

... no Cost Co. Run at 36/38psi at ambient or whatever road comfort you desire (below 34psi on asphalt will lead to eventual uneven wear on these larger format rubbers). I have discussed this one before with the guys at Bob Janes. This is general advice only.

 

[Dokatd]

Costco is definitely wrong, unless you are looking for max load.

For daily driving on my 315/60R17 Goodyear Territory MT’s I run about 30psi. Chalked the tires to set optimum pressures.

 

[MurphyMurph]

E-rated tires have a stiffer sidewall and are designed to run at higher pressure than D-rated tires. This also means that running at lower pressure won’t cause as much deformation because the sidewall is helping hold the weight of the vehicle instead of air pressure. Running at lower pressure will make it ride smoother, but will increase wear on the shoulder blocks and decrease handling and likely stopping performance.

I change my pressure all the time just to see how it rides. I’m currently at 40psi front and 42psi rear on stock KO2s. I was running 36 psi all around for a while but wanted to help out with fuel economy now that our gas has switched to the higher ethanol content “winter blend”.

Hope that helps!

 

[MurphyMurph]

I just switched out the 255-70-18 KO2s that I got with my rig for 285/75-17 HD-Terrains on AO XT rims.

Pics of the new wheel/tire combo?

 

[wolftimj]

 

[Zimm]

Seems like odd advise. E has a stiffer sidewall and is less likely to deform. although results may vary brand to brand so a direct comparison is really stupid. I'd error on not pissing off the Gren TPMS gods and keep it the same.