Ok... This is a silly question but, I'm curious. I have 305/70 R 16's on my jeep with 16X8 wheels. They carry a load range D just like most every other 16" tire. Obviously the side wall being 8 ply instead of 6 ply means it will hold the weight of the Jeep with less air pressure. I am wondering what other people with D rated tires are running for air pressure.

I started at 35lbs. I noticed that I was only running on the middle of the tire. Literally the outsice inch wasn't touching. I've been airing down a couple of pounds at time and trying again. I'm down to 30lbs. And still not sure I'm flat. I check it when I get to a nice flat surface(concrete pad at the gas station).

 

For a 33" tire, I typically run them at about 28 psi and on a 35" tire, more like 26. If you really want to know how to run an even foot print, you need to do a chalk test. Basically, mark a section of your tread with chalk, roll it to see what kind of a foot print it leaves and let out air until it's even.

 

I've always used a little water for checking the foot print. My biggest problem of doing this all at once... playing with the pressure... is haveing a flat surface. here in New England flat surfaces are scarce... lol

 

Yep - chaulk test it. That's definitive. If you do not have a flat suface, run over sheet of 3/4" plywood, etc.

 

Are you guys using chalk from a chalk line or some other type? This is the first time I've ever heard of this method. Out here we use water and textured concrete

 

i take a cup of flour and draw a thin line just in front of each tire... drive forward over the flour and voila... you should have a line of flour all the way across your treads... you actually only need two lines... one for the front tire (more weight) and one for the back (less)... i will try chalk too... but flour is easily found in most households