[QUOTE="GJeep;4063500"] Sorry, no way that rubber which doesn't touch the road would wear like you say.
You could be right though, if the tire is driven daily with very low pressure, say 20psi.
Sorry, no one said that rubbing not touching the road would wear anyway. Every vehicle tells you what psi would be best for the weight of your vehicle, yes vehicle weight changes with all the bumpers and all. But run your tires at 20psi (with a heavier vehicle than it was stock, at a lower psi than called for stock it will put more pressure on the shoulders of the tires even with your chalk showing that the center of the tire is touching pavement. Just as over inflation wears the center of your tires more it does just the same with under inflation and ppl don't realize that bc of chalk test. Keep under inflating and your chalk will show u a nice print but when it comes to pavement the tires will still feel more pressure on the outsides

 

Oh, no offense was taken, and sorry if I came off that way. I appreciate the advice.

 

i run 25psi in my 41" irok radials. seems to do fine

 

I run 17 in my 37" stts.

 

that seems really low for a 37 on pavement

 

Typo? 27 sounds more realistic..

 

What you’re saying is that the chalk test isn’t accurate enough.

With dry tires & road, the chalk sticks to the tire rather loosely, it doesn’t take much to brush or grind it off. A few tire rotations on asphalt, wipe the chalk off, more so where there’s more pressure.
It’s accurate within about +/- 2 psi, which is accurate enough.

Did you actually do the chalk test, and used the psi according to the test result long enough to find out that the test was misleading?

I did, and worn out 2 sets of different tires on different vehicles, both with 30 psi, which was what a chalk test suggested. Tread wear was even.

With Jeeps that offroad, it’s harder or even impossible to assess the long-term chalk test accuracy.
The reason for that is that there’s much more tire wear off road than on roads, and we don't use the chalk test psi when offroading. We usually deflate to lower pressure, so the tread doesn’t sit flat.
This prevents us from getting the true picture of on road wear.
(There’s a simple solution for this… make your Jeep a mall crawler… )

 

Thank you for useless info but this was all about PAVEMENT driving. I think everyone here already knows why we deflate tires when off roading. Under inflation is gonna put more pressure on the outsides of your tires with every tire. Keep playing with your chalk but talk to any manufacturer or or any tire distributer and they'll be glad to show u a picture that you could have saw for yourself on the Internet of what under inflation does to tire wear on the pavement.

 

And just to clarify I didn't recommend going lower than 30. When the vehicle calls for around 30-32 and then your adding steel bumpers along with a lot of other weight the answer wouldn't be going with less air or you'd be seeing heavier trucks with 30 psi instead of 65-80, keeping your pressure in the 20's is too low

 

As you recommend consulting with tire manufacturers, you surely follow their silly pressure recommendation with great devotion, and drive on 35psi bricks...

Your reply is way off the various points in my post.
Go ahead and consult with anyone you wish, while I'll stick to years of actual experience, and lets end this pointless exchange.