Ideal gas law. Higher temperature = higher pressure. The benefit of pure nitrogen is that you don't get any Oxygen inside your tire slowly eating away, and you get no water vapor which could cause drastic changes in pressure.



That being said, 32 cold is a good place to start for street use. If you notice your centers wearing faster than your edges, then lower 2 psi. If the edges wear faster than the center, then raise 2 psi.

On the other hand, if you're doing high speed pulls on the highway, then aim 36-40 psi hot. For every 10 mph you're going over 80, raise the PSI by 1. Do not go beyond the PSI on the tire's sidewall, when measured cold.

For tracking/spirited drives, you want to target 36-38 all around depending on the tire. Lower pressure may FEEL better, but not necessarily faster.

 

Mike, why start at 32 cold as a baseline when OEM recommendation is 35? What's the benefit of dropping down 3 PSI to start with?

 

my main concern is hitting a pot hole and jacking up my rim... i figure if the psi is alot higher then it would take the pressure off the rims if i hit a pot hole and put all the pressure on the tires. i dont know.............

 

On the basis that most people who read this board are enthusiasts, and are likely to drive harder, faster, and are probably dropped a wee bit on springs/coils. Camber heats tires hotter/faster, as does toe

Between those factors, the hot psi will likely end up similar to a bone stock car at 35 cold.

Ultimately, hot PSI is the only thing that matters.

One of the best things you can do is to purchase a $2 digital tire gauge at your local store, and measure your psi immediately after a drive, and adjust; the tires never heat evenly.

 

That being said, 32 cold is a good place to start for street use. If you notice your centers wearing faster than your edges, then lower 2 psi. If the edges wear faster than the center, then raise 2 psi. [/quote]

this is the same rule of thumb I do on my stock tires. I ran 38 psi and notice 1/2" to 1" area from the edges is not part of the contact patch. You can literally see the "dirt and dust" ring on it, as suppose to the darker black rubber center area.

So I now ran with 35psi and the contact patch is even across the width of the tire, except for the 1/4 to 1/2 in. on the edge for going too fast around the corners!

 

Hankook V12 evo's here with 35psi front and 40psi rear.

 

Perhaps that’s for the sports model. The tire placard for my Journey says 33 psi for all four OEM tires and that’s what I run.

 

Correct.