Tire PSI & MPGs

[Jeepstin392]

I couldn’t figure out why my average MPGs were running 17mpg+.

Well, the last mechanic, deviated from my preferred 30 psi to a fine, 45psi.

My MPGs went from 14.8-15 overall average to over 17.

 

[ParadigmDawg]

I run 29 psi and get 9-10 mpg. Seems fine to me.

 

[Jeepstin392]

I run 29 psi and get 9-10 mpg. Seems fine to me.

I dropped back to my preferred pressure. I never run pressure higher than 30-32.

 

[Earl 392]

I couldn’t figure out why my average MPGs were running 17mpg+.

Well, the last mechanic, deviated from my preferred 30 psi to a fine, 45psi.

My MPGs went from 14.8-15 overall average to over 17.

45 psi would ride like a rock 17 on the Hwy was the best I ever got 15 is average. I run 35s at 32 psi (nitto trail grapplers c rated)

 

[Shark01]

Really don’t understand the low tire pressures for street use, they make the steering/handling sluggish and sloppy.

I run 37-38 psi, get 16.5 mpg, and it rides, steers, and handles fine.

 

[Phil921]

Really don’t understand the low tire pressures for street use, they make the steering/handling sluggish and sloppy.

I run 37-38 psi, get 16.5 mpg, and it rides, steers, and handles fine.

As much as some of the roads around me can feel like they are trails, I'm in this camp also. If it's your DD and/or highest percentage on pavement, IMO it just makes sense to run a higher tire pressure... I also run 37-38psi (cold).

 

[prodriquez]

I live in Colorado. I run 30 psi on the street, on 40’s, and the only time I worry about MPG’s is when I’m off road.

On-road SPG = 8 to 14
Off-road MPG = 4.5 to maybe 6

Biggest factor = my

Needless to say… I definitely understand the ‘range anxiety’ that all those EV owners have

 

[Earl 392]

Really don’t understand the low tire pressures for street use, they make the steering/handling sluggish and sloppy.

I run 37-38 psi, get 16.5 mpg, and it rides, steers, and handles fine.

I like my tires as square as possible on my lj I ran 25 street 10 dirt load range E At 38 they start to round. Then they imho will wear unevenly

 

[onfire392]

37psi rolling out onto my wet driveway did not contact the entire tire. Two dry edges. Took 32 front and 30 rear to get close. Still not perfect.

 

[Earl 392]

37psi rolling out onto my wet driveway did not contact the entire tire. Two dry edges. Took 32 front and 30 rear to get close. Still not perfect.

Exactly my point that cold 32 will turn into 35-36 on highway travel especially in hot conditions. Thanks for the post

 

[Jeepstin392]

Really don’t understand the low tire pressures for street use, they make the steering/handling sluggish and sloppy.

I run 37-38 psi, get 16.5 mpg, and it rides, steers, and handles fine.

Preference.
Like anything else modified on any vehicle.
Ride quality is shite above 40 psi.

 

[guruman]

Crisp, responsive steering and handling are an illusion on a tall 6,000 pound 4x4.

I embrace it. Running 28psi all around. It makes the potholes less jarring, and maximizes launch traction.

 

[JESSE'S 392]

Really don’t understand the low tire pressures for street use, they make the steering/handling sluggish and sloppy.

I run 37-38 psi, get 16.5 mpg, and it rides, steers, and handles fine.

I agree, I used to run 32-35 ,, I got new 37 inch Mickey Thompsons and started runing 38 psi and still runs great I get around 14 to 15 mpg I think that's not too bad. I was getting 10 to 11 mpg

 

[@JC]

Exactly my point that cold 32 will turn into 35-36 on highway travel especially in hot conditions. Thanks for the post

You, sir, must not be using the dealership's special nitrogen tire fill.

 

[Earl 392]

You, sir, must not be using the dealership's special nitrogen tire fill.

Off roading too often air down air up . The air we breathe is 80% nitrogen

 

[@JC]

Off roading too often air down air up . The air we breathe is 80% nitrogen

Missed the sarcasm, eh?

 

[Earl 392]

Missed the sarcasm, eh?

Just the facts . Some Jeep 392 ‘s may never see dirt .
If I owned a Demon I would drive it but I wouldn’t take it to the track . However I would fill those tires with nitrogen. For Jeep to do real R&D they should run these 392’s and all other rubicon models in the dirt until they disintegrate and fix all common issues then we would all have a solid product. Street jeeping doesn’t help the cause. No offense to anyone who doesn’t off road .Jeep loves us all

 

[Tank2112]

Crisp, responsive steering and handling are an illusion on a tall 6,000 pound 4x4.

I embrace it. Running 28psi all around. It makes the potholes less jarring, and maximizes launch traction.

Ever tested 0-60 with 37psi?
May gain slightly due to less rolling resistance? I realize there is a point of zero gain.

I've been running 36psi -37psi, just seems to roll easier.

 

[guruman]

Ever tested 0-60 with 37psi?
May gain slightly due to less rolling resistance? I realize there is a point of zero gain.

I've been running 36psi -37psi, just seems to roll easier.

I have not and that's a good point.

It would be interesting to test and quantify the amount of rolling resistance at differing tire pressures. I know my fuel economy has not been drastically affected at 28 verses 40.

 

[MDrums]

I like my tires to wear evenly. 37psi cold per manufacture wears the center out. Yes you get better MPG but tires do not wear properly.

I found for my 24 392 that 32 front and 30 rear has better road contact and even wear. I tried 34 from and 32 rear and front was ok not perfect but rear contact path was not as good as 30psi - cold. Jeep is sock on stock OEM BFG tires.