iannis

What pressure should I inflate my tires at, for on road everyday commuting?

I have Cooper STT's and as mentioned in the header dimensions are 245/70/R17.

PS What is the factory recommendation for rubicon installed 255/75/R17 MT's?

jkkat

BFG MT KM DT's factory wants 37 in them, i run 35

SBlair

Look at the tag on your door. Typically the inflation pressure is due to load rating and not tire manufacturer. That said, I run 35psi in my coopers!

iannis

My door tag says 35 however it is for factory dimensions which are 245/75/R16; and I have changed to 245/70/R17.

BTW for the time being I run at 35psi, however worry that it is too high, therefore the question towards the forum.

jkkat

If you are that worried about it then due the chalk test.

iannis

What 's the chalk test?

JMP8562

i have stock 17" and i run 42# it is a stiffer ride BUT i drive about 100mi to and from work and im getting about 23-24 mpg

pearl-drum-man

Put a thick line of chalk across the tread, drive the Jeep for a few revolutions, then look at the chalk. If it wears evenly, your pressure is good, if it wears more in the center, then you're over-inflated and thats how your tread will wear, if it wears more on the edges then you're under-inflated.

You can also do a similar test by driving the tire through some water and then looking at the tread pattern it leaves, again looking for the same indicators. The chalk test is more reliable.

iannis

THNX all, I will try the chalk test.