• NAXJA is having its 18th annual March Membership Drive!!!
    Everyone who joins or renews during March will be entered into a drawing!
    More Information - Join/Renew
  • Welcome to the new NAXJA Forum! If your password does not work, please use "Forgot your password?" link on the log-in page. Please feel free to reach out to [email protected] if we can provide any assistance.

Tire Pressures

Rocketman

NAXJA Forum User
Location
Bolingbrook, IL
Did the obligatory search.... couldn't decide on Mod or OEM forum so it's here!

What's an OPTIMUM, highway pressure for running a BFG 31X10.5?

BFG's site is pretty sketchy saying max load per tire at 50psi is 2250lbs

I'm at 32 on the road 18 on the trail. Can I go to 40, 45 to improve mileage??

I know it would be a harsher ride but willing to trade off with gas prices lately.

I know my ?'s pretty specific to the tire but I'd think any 31 would be close to the same spec.
 
Chalk across the tire and drive a straight line for a short distance. The chalk should wear off nearly across the entire tread with slightly less at the shoulders. One problem with doing this on BFG's is they seem to have a pronounced crown to the tread. If you run them at higher pressures you will wear the center down more quickly. If the tire is rated for 50 psi, youcan run it up to that with no adverse effects other than tread wear. My 32-10.5 Swampers are rated for 50, and I run them at that on the road, but they have a very square profile, and wear very well.
 
26 to 28 is about right.

The recommended pressure for stock tires in 205/75, 215/75 and 225/75 is 30 psi. For the tiny 195/75 tires that came on early Base models the recommended pressure was 33 psi. You don't need more pressure with larger tires ... you need less. The only reason to run 28 is to reduce sidewall flex and heat build-up.

If you want to run 40 psi or more for gas mileage, just remember that the only reason that halps gas mileage is that it lifts the edges (shoulders) of the tread off the pavement, so you're driving only on the center portion of the tread.
 
Would that hold true (26 to 28 psi) for a set of Rubicon tires? (245/75 R16 MT/R's, about 31's)

I had my stock tires (225/75 R15 WildCountry XRT's) dialed in pretty well at 32 psi for good wear patterns and ride, but now I've got to figure out the psi for the new ones.
 
Eagle said:
26 to 28 is about right.

The recommended pressure for stock tires in 205/75, 215/75 and 225/75 is 30 psi. For the tiny 195/75 tires that came on early Base models the recommended pressure was 33 psi. You don't need more pressure with larger tires ... you need less. The only reason to run 28 is to reduce sidewall flex and heat build-up.

If you want to run 40 psi or more for gas mileage, just remember that the only reason that halps gas mileage is that it lifts the edges (shoulders) of the tread off the pavement, so you're driving only on the center portion of the tread.

Eagle is 100% dead on here.

You may gain mileage by running stupid high pressures, but you will lose tire life.

Don't bother. Anything 31 or bigger sizewise I usually run somewhere around 29-30 psi or even less for bigger or non street tires. Otherwise the ride will suffer and the tire wear will be even worse.
 
Do the chalk on the tread thing, like Explorer suggested. Rim width enters into the equation, because you need lower presure on a narrow rim than you do on a wide rim to keep the tread flat on the pavement. On very narrow (for the tire size) rims the "right" pressure for tread contact may be too soft for high speed cruising due to sidewall flex ... in which case, you bump it to 28 and call it done.
 
Back
Top