I got in my 215/75/15 Hankook MT RT01 tires today. They say 50 psi on them but I have a light wagon so what psi should I have them at?

for the street i'd go with what is stamped on the A pillar, as for mudding, as low as you feel comfortable with, you don't want to pop a bead. use some chalk and put lines perpendicular to the rotation of the tire, across the tread, and if its leaving spots behind, change your pressure. if its only in the middle, lower the pressure, if its only on the sides, increase it.

use some chalk and put lines perpendicular to the rotation of the tire, across the tread, and if its leaving spots behind, change your pressure. if its only in the middle, lower the pressure, if its only on the sides, increase it.

 

I never thought of using chalk. That's a good idea.

I didn't air down at the last event we were at, the car's so light, and it just makes your sidewall's more vulnerable. if you've got good strong sidewalls (MT...probably, mine are just all seasons) then it might help.

 

btw, the jeep guys said to run about 15psi, and that's even on a wrangler, which is pretty light (probably not as light as a wagon, but close, with no top/doors).

Good rule of thumb is run half pressure to what you run on the street.

 

Personally I dont air down my tires. I have cheap ATs, no extra side wall tread to use, and I'd rather have the extra inch of clearance vs. whatever traction I gain. I ran at half pressure and didnt notice a difference; however again I do not have good tires that will benefit from airing down. If I had some super swamper sx tires I'd air down for sure!

 

Run at 25psi next time you are out on the trails and see if you like it.

I air down to about 10-15 psi for snow ice and rocks, and to about 20-25 psi for regular offroading. At 10 psi I don't think my shocks/struts even really do much, all the suspension is in the tires.

50 psi is way to much for the street on that car!! try running around 28 - 32 psi o the street. As far as airing down on the trail, I have never aired down the tires on my loyale, but on my old toyota 4x4 I would run 8 - 12 psi on the trail. Experiment with different tire pressures on the trail and see what best suits you for your vehical and driving style. Just remember, if you are going to air down for the trail, learn how to set the bead on a tire out on the trail, because without bead locks, you will pop a bead sooner or later.

50 psi is way to much for the street on that car!!

 

Why? It says 50psi on the tires. I'd expect some good gas milage at 50psi and a stiffer ride but I wouldnt think it's a bad thing.

bumps are going to be like kicks to the rump roast w/ pressure up at 50psi... even if you have a soft suspension...

Not neccessarily. The tire manufacturer sets inflation by differing factors. Which include sidewall strength, the rated capacity of the tire, footprint and such. Ideally, water testing is probably about the best way to check the footprint from air pressure settings. Sand is another good way to check that. Ideally, you could figure the weight ratings for you tire and then take the weight of your car then divide the weight of your car into the rated capacity to determine the percentages. Then adjust the pressure according to that percentage.

 

Probably clear as mud now.

Sweeet.

ken's right there. 50 psi is a lot to be running on a subaru. most of my mud terrains i have had sat flat on the ground around 25 to 30psi. depending on the tire type and weight capacity. either use chalk, or water and or a combination of the vehicle weight to tires method to find a good ball park for your tires.

as for offroading pressures...

quick short easy trails that i know i can get away with out airing down. i stay at highway pressures.

sand i'm usually around 9psi to 13psi, if the sand is like real deep and soft dune sand. more compact sand i usually don't bother airing down till i have problems.

rocks and roots... i'm usually between 13 to 18 Psi.

mud it all depends 13 to 25 psi...

play around with your pressures to figure out what you need. and remeber these were on 27" tires to 31" tires. so there's a lot more sidewall than stock size tires. also take into the fact ambiant air pressure is usually 12.5 psi at sea level and decreases with elevation. so take that into account, when running anywhere near or below that pressure, you run a more likely chance of popping a bead. so be warned.