What Tire Pressure are you running?

re-rx7

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#1
Ive been running the factory reccomended 36 up front 39 out back but I feel 32 up front and 36 out back wouldaid in traction and handling. What are you running?
 


lessard.dcj

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#2
factory numbers. although i think it may be too high for the winter tires to get max traction.
 


Perfblue15

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#3
I personally run 34 all around and the car seems to feel much less twitchy and more planted.
 


OP
re-rx7

re-rx7

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Thread Starter #4
Good info so far.
 


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#6
Ive been running the factory reccomended 36 up front 39 out back but I feel 32 up front and 36 out back wouldaid in traction and handling. What are you running?
Isn't it 39 in front and 36 in the rear?

Anyway, I have 215/40/17s, and I run 37 in the front and 34 in the rear.
 


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#7
I run the factory recommended pressures. If you live in an area with lots of pot-holes, too low pressure could result in a busted wheel.
 


haste

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#8
factory pressures with 205/45 tires on oem wheels. I use the same pressures with the 40 profile on 16.35lb aftermarket wheels and i cant tell a difference in the "harshness" between the two sets.
 


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#9
What tire pressure are you supposed to go off of with aftermarket wheels and tires? I have 16x7 TD wheels with BFG sport comp 2's. Do you go off of what is posted in the door jam "factory pressure specs" or do you go off of your new tire's sidewall? I would really appreciate any help with this.
 


M-Sport fan

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#10
^^^^The numbers on the tire's side wall are merely the MAX inflation pressure that particular tire can safely handle without damage/blowing off of the wheel, it is NOT a 'recommended' inflation pressure! [nono]

With an aftermarket size setup, I would start at the door placard suggested pressures, and then adjust up or down from there, depending upon handling needs, and ride harshness. ;)
 


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#11
Okay so now we know the sidewall is a MAX pressure and not a recommended tire pressure. Great! So does this mean that we go with the recommended 36 up front 39 in the rear?
 


Zormecteon

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#12
Okay so now we know the sidewall is a MAX pressure and not a recommended tire pressure. Great! So does this mean that we go with the recommended 36 up front 39 in the rear?
It's the other way round.. 39 up front, 36 rear. .. .... I've mentioned it before in other threads... the recommended differential is a way to balance the cars handling. The Corvair had such a difference front to rear, and its reputation for dangerous handling was the result of those differences being ignored. My Healey also has a recommened difference, with the rears being the higher. It can get "tail happy". .. and this helps cure it.
 


M-Sport fan

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#13
It's the other way round.. 39 up front, 36 rear. .. .... I've mentioned it before in other threads... the recommended differential is a way to balance the cars handling.
THIS!!!^^^ [thumb]

My Z28's "recommended" pressures were 30 all around, but I ran 6 pounds higher in the front than the back (usually 40F 34R), even on the street, for just this reason above!!
 


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#14
if your running different tires/wheels... try oem air pressure.

chalk the tires across the width of the tread. drive forward and rearward without turning at all on level ground.. check the chalk. if the center is gone and outside is still there, lower air pressure. if outside is gone and center is still there raise air pressure.
if you auto-x your car then its whole different thing.

I learned this from running E load tires on a Jeep JK that came with C load tires. I had to run 27 psi in them. OEM was 35 I think and the E load tires sidewall said something like 70psi.
 


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#16
if your running different tires/wheels... try oem air pressure.

chalk the tires across the width of the tread. drive forward and rearward without turning at all on level ground.. check the chalk. if the center is gone and outside is still there Tyre shop Harrow, lower air pressure. if outside is gone and center is still there raise air pressure.
if you auto-x your car then its whole different thing.

I learned this from running E load tires on a Jeep JK that came with C load tires. I had to run 27 psi in them. OEM was 35 I think and the E load tires sidewall said something like 70psi.
i have the car settup for light load tire settings. Recorded is 35.8 and close to 39 in the rear. haven’t checked what my pressure were for awhile and noticed with the colder winter temps i was 5 psi less than recorded. No light ever went on. i pumped them back to the recommended pressure but the car definitely feels bumpy and too much air. Prob will get much better MPG but wonder if that recommendations is for street tires. what is everyone else running for everyday driving that has some type of All terrains on
 


Intuit

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#17
If you look at your door jamb sticker, you'll notice that the rear pressure is set significantly lower than the front.

Maintain that ratio. The vehicle has a tendency to fish-tail when the rear is set significantly higher than the front.

Regarding the question:

Door jam +3 ~ 5 PSI up front.
Rear pretty much stays at door jamb; +1 ~ 2 at most.

I remembered while leaving the street that I forgot to set the pressures after a tire rotation. From a stop light, took the left turn aggressively and turned into the General Lee for a moment...
1723691763085.jpeg
 


Dialcaliper

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#18
Going away from the XL rated 17” tires to an SL rated 16” tire means lower pressure for equivalent load. BFG also recommends aiming for 35psi hot as a generic starting point for these tires, so it’s in the ballpark

I started with the equivalent to the OEM 39/36 which is 32psi up front and 29psi out back (maintaining the 3psi split). Through various adjustments, I’m currently running 34psi front, 32psi rear (on 215/45R16 BFG Rivals).

Currently it’s been working well with the BFGs. Switching to Bridgestones soon as I’m due for a set of tires, so I half expect to end up with slightly different pressures.
 


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#19
I run 39 front 36 rear. I rotated the tires without changing the psi so I had 36 in front and 39 rear and I spun out on a twisty on ramp. Scared the shit out of me. Lucky I didn't hit anything. I will never do that again. Stick with factory recommended pressure. Don't make my mistake.
 


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