Spare tire psi?

[grady2hig]

Should the spare tire psi be less than the other tires? Or does it not matter.

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[Chocolate Thunder]

My logic is to keep it a few pounds higher so in case it loses a few psi it won’t be too low or flat. I can always let a few pounds out if need be, but without on board air there’s no way to air it up if you’re not somewhere convenient when the need for it arises.

Why would you run it lower?

 

[multicam]

@Chocolate Thunder

I can’t imagine why anyone would run it lower, except maybe.... maybe... they’re thinking that at a lower PSI it will be under less stress, or pressure (literally), and may last longer because of this? I don’t know, I’m reaching.

By the way, sound logic. I’m going to put a few more pounds in my spare next time I run low on gas.

 

[grady2hig]

Well I was thinking that once you put it on the Jeep the weight of the Jeep would make it higher. Nevermind...im overthinking

 

[Arterius2]

Well I was thinking that once you put it on the Jeep the weight of the Jeep would make it higher. Nevermind...im overthinking

Even if it were so, letting air out is always easier than filling it back in. I always keep a pressure gauge in the Jeep.

 

[UNC Rubicon]

I run mine around 15lbs. My reasoning is if I clip the tire coming off an obstacle, it will have more give and be less likely to warp the tailgate. It’s a stretch, I know. But, I want to take all precautions in case it gets hit. With that said, I have OBA so I don’t have to worry about filling up when needed.

 

[Rubicon_LA]

keep it lower maybe to have less stress on a tailgate and hinges

 

[Headbarcode]

I keep all 5 the same and rotate every 5000. If nothing happened to the spare when it was rolling, it'll be just fine while hanging in the breeze.

As part of my preventative maintenance, my gauge kept in the center console is used all around on the first of every month and after a rotation. Takes me an average of 3 months to rack up 5000 miles

 

[jimmyzwheelz]

keep it lower maybe to have less stress on a tailgate and hinges

Help me understand how lower air pressure reduces stress on the tailgate??

 

[Rubicon_LA]

Help me understand how lower air pressure reduces stress on the tailgate??

Less air = less weight of the spare wheel/tire = less stress on the liftgate and hinges.

 

[Chocolate Thunder]

Yep. Because that extra few psi of compressed air is REALLY heavy!

 

[Rubicon_LA]

Yep. Because that extra few psi of compressed air is REALLY heavy!

Lol, I know. Theoretically it will be lighter, though practically a few gramms here and there is very insignificant with wheel/tire weight.

 

[TJ2018]

Less air = less weight of the spare wheel/tire = less stress on the liftgate and hinges.

While there is some truth to this concept, the weight of the air is insignificant compared to the weight of the tire/wheel. Estimates are that the weight of the air in the tire is less than 0.05% of the total weight. And since that's on a typical automobile tire I would hazard to guess that it's more like 0.025% . If the tire/wheel weighs 65# that works out to about 0.3 oz. when full of air compared to no air.

 

[RockAltered]

315 70 17 on stock Rubi wheel fits the carrier with 25 psi but 35 psi doesn't on my stock rig.

 

[ParadigmDawg]

315 70 17 on stock Rubi wheel fits the carrier with 25 psi but 35 psi doesn't on my stock rig.

I run 10 psi in my spare on the TRX. Anything higher and it will hit my track bar. OBA so no biggie and it is common for us Hellcat truck guys on 37s.

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