[Elwood]

I have been tinkering with the air pressure in my MTR's on my Rubicon. (Stock size from the factory)

I have been running 19psi on the street for seven thousand miles now and have NO cupping or uneven wear at all. Before, I was having a lot of problems and was forced to rotate every oil change to keep my sanity.

The only reason I am going to rotate is because the rear tires just need to be put on the front so they don't wear out quicker.

The tread is nice and smooth and as quiet as an MTR can get.

[Xenophage]

That's a little low. Door says 30 (or close) and that what I run them at. They have been wearing fine, I have 68,000 Km and still original tires.

Check the Rubicon Owners Forum (ROF)they have done a lot of testing with pressures.

[BlueFlame]

That's pretty low. Low enough to hurt driving performance (squishy wallowy when cornering) and it's costing you gas mileage. With that size tire around 30 is going to be the ballpark.

[fish4life]

you definitely havent figured it out if you're running at 19psi

[Elwood]

I have been at everything from 30 on down at 2-3 psi increments with terrible tire wear. Granted, if these were "regular" tires for any Jeep, 19 would be awefully low, but these are the stock "E" rated tires. They aren't even squatted at this pressure.

While it may be costing me gas milage, in real world dollars, how much? Not much, it is a brick in the wind. One or two mpg does not matter to me much. Better tire wear is a little more important for me.

At the higher pressures, it would not be any time at all and the tires would cup and the front part of the bars or blocks of the tread would wear worse than the back part of each bar. It would make driving a terrible experience and increase noise. Not bad when the top and doors are on, but summer driving with the top and doors off was a bit annoying.


While I am not an expert, I feel that with the "overkill" of a sizewall my stock tires have, 19-20 psi is not a terrible pressure to run at, especially given my personal driving habits.

[hecubus]

are you using a decent air-pressure guage? I speak with no authority on this but I've never seen an accurate 'pen-type' guage or dial guage on the pump itself...

[Elwood]

I use one of those digital things. Only a couple bucks each and they are handy for the glove box. I have double checked it a few times with a decent pen guage as well. As the pressures started to dip below 25, I was starting to second guess my guage as well as my methods, but I was willing to try it in an attempt at better tire wear.

[BlueFlame]

You maybe get away with it due to those stiff sidewalls.

Better tire wear at the expense of gas mileage is false economy with gas at $3+ per gallon. Tires are cheaper.
If you could increase tire life by 25% (which is doubtful) but lose 2 miles per gallon (very easily achieved) It would STILL cost you more in gas than in more frequent tire replacement.

[97 SRH Jeep]

have you ever got an alighnment to be sure that your tire wear issue isnt just caused by properly filling your tires?

[jsbarks]

check your balance for tire wear...
Tie rods and struts also cause the problems on vehicles.
I would run them @ 35psi. As that will give you the best mileage, best tire wear but not as soft as a ride.