You're going to say something is wrong with his tire without knowing the size of his or posting the size of yours? We need to know diameter/height before jumping to those conclusions with psi.

 

agreed on my range e 35 x 12.5 on a 8" rim i ran 20-22

 

He did tell us his tire size.

 

i see a rim a width no tire height...

 

I'm still experimenting with my 37's but it seems 21 is still to high. Not trying to steal the attention here just illustrating that you can't make a judgement wether 26 is too high/low without some kind of volume.

 

He gave tire and wheel width only.

 

I never said something is wrong with his tire. I said at 26 psi on his C rated tire the pressure is not correct the way the chalk line is worn off unless he is turning while doing the test. mine 285/75-17's psi 27 cold. 8000 miles and perfectly even wear.

 

15x8 Black Rock D Window alloys. 35x12.5x15 General Grabber tires. I'm not turning the Jeep when I do the test, I know that causes incorrect results. I'm chalking completely across the 2 different tread lug patterns and driving approximately 50 yds on a flat surface at around 15-20 mph. The tires only have 2000 miles on them and I've been running them at 28 psi until today when I dropped them to 26 and did the chalk test.

 

My point is, you can't make that judgement without knowing diameter/height. A 33 will require more pressure than a 35 etc etc

 

I would try again around 22 and see how your results look. Do you have a pretty light build?

Edit: the fact you have 15's means more air volume so you will run a lower pressure than a 35 on a 17. If someone would like to correct me with facts or evidence, I'm all ears. I'm certainly not the ultimate judge.