I am running Cooper Discoverer A/T 3 275/70/r18's and I am trying to figure out the best psi to run them. My alignment guy said at least 65psi (rated at 80) but not sure on this advice. This is for the street driving part of the jeeps life.

 

Do a chalk test to see how they are wearing. 65 lbs way too high for these vehicles. I would drop down to 35 lbs or so and go from there using a chalk test

 

What he said.

 

I run my 35s at 32 to 35pds. The tires seem to wear good at that pressure

 

I ran my 33" km2s at 27lbs and they wore perfectly. Had about 20k miles on them when I went to 35"s and my old km2s still had 85% tread when I sold them. Now with the 35" terra grappler m/t rated e, I am running 25lbs and it seems to be doing fine. With an e rated tire, the jeeps weight causes the tire to flex very little so its good to run a lower pressure.

 

I had my lift and 35" mud grapplers put on a few weeks ago and have since been looking for more of a stock feel, was slightly rough on bumps and imperfections in the rd. took it back to the shop today because he wanted me to test drive his with the same set-up, only he had additional control arms and goodyears. It drove like stock. He then drove mine and said the issue was with the tires, sure enough we checked and they were at 50psi. lowered to 35psi, and its night and day.

 

I run my 33's at 25. Will do the same with the 35's once they go on.

 

65 is WAY too high. Nice tires though.


We run these exact tires on a utility body work truck that weighs around 10,000 pounds.

 

You could honestly go lower than that with those tires

 

How low would you recommend? and would any lower make them wear quicker?