busa250

Trying to get a grip on what street PSI i need to be running. Was at 36 and just went down to 30 on toyo R/T 285/75r18's.

Jeek.OlllllllO

I'm running 25 on my nitto mud grapplers but I have added more stuff to it so I might go up to like 30. Do the chalk test and where you should be at

sa29560

Yes, chalk test.

I'm at 28 front, 25 rear on 8 ply 315 on 16s.

robsjeep9

28-30 PSI with my 35" Duratracs in winter 28 PSI with my 37" MTR's .... Chalk test helps as mentioned

karls10jk

Tire width and rim width are two factors to be considered with this topic. The other elephant in the room is "what purpose do the tires serve"?. If they're for maximum mpg's and a little stiffer ride then pump them up. If you're looking for a "flat" wear pattern, drop the psi.

Stock wheels with 275 cooper's and 255 goodyear's- both at 34-36 psi for a flat pattern and maximum mpg. 40 psi would probably give me another 1/2 mpg, but is it worth the reduced tire life and ride quality, nope.

thechad07

33/12.5 15. Usually have them at 25 psi.

busa250

My ride sucks, super rough. The suspension company recommended 30. I was at 36. I am going to do the chalk test tomorrow. I just do not want to ruin my tires.

Chefbrujo

Im at 28psi with my falken wildpeak 285/70/17's
Iv got a heavy jku, bumpers, sliders and winch. Chalk testing yielded me my psi for best wear. I had run as high as 38 before and got a little better mpg (about 1.5+) but the ride was too stiff for me and I want to make my tires last. Tires be expensive!

busa250

Shot it dont think my fuel economy can het much worse. I am running 13.5 in the city.

Chefbrujo

That's about exactly what I'm gettin in the city, (13.5) hwy it will go up to 14.7-14.8. The more hwy I drive it will hit 15-15.2

I'm a 2010 3.8. Runnin a superchips gas saver tune with an aftermarket exhaust.