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Correct tire pressure? by RilesOfSmiles
Started on: 09-07-2013 11:25 PM
Replies: 16 (606 views)
Last post by: BlackEmrald on 09-08-2013 10:53 PM
RilesOfSmiles
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Report this Post09-07-2013 11:25 PM Click Here to See the Profile for RilesOfSmilesClick Here to Email RilesOfSmilesSend a Private Message to RilesOfSmilesEdit/Delete MessageReply w/QuoteDirect Link to This Post
My front tires are rated at 35 psi max press and my rears are 44 psi max press. I keep all 4 at 40 psi. Is this a good idea or not?
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Report this Post09-07-2013 11:28 PM Click Here to See the Profile for trotterlgClick Here to Email trotterlgSend a Private Message to trotterlgEdit/Delete MessageReply w/QuoteDirect Link to This Post
Probably not.
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RilesOfSmiles
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Report this Post09-07-2013 11:36 PM Click Here to See the Profile for RilesOfSmilesClick Here to Email RilesOfSmilesSend a Private Message to RilesOfSmilesEdit/Delete MessageReply w/QuoteDirect Link to This Post
Could something go wrong? The car seems to wander a bit if the pressure is much lower
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DaytonTD
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Report this Post09-08-2013 12:25 AM Click Here to See the Profile for DaytonTDClick Here to Email DaytonTDSend a Private Message to DaytonTDEdit/Delete MessageReply w/QuoteDirect Link to This Post
When it is not enough pressure the outside of the tread wears more, and too much pressure the inside middle of the tread wears more. 5 PSI difference is nothing really to be concerned about. 20 PSI low or high on a 40 PSI tire is something to worry about.
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trotterlg
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Report this Post09-08-2013 12:34 AM Click Here to See the Profile for trotterlgClick Here to Email trotterlgSend a Private Message to trotterlgEdit/Delete MessageReply w/QuoteDirect Link to This Post
In any case running a tire over it's maximum rated pressure is a bad idea, you are running the front over their rating. When you do that they are more easily damage by road hazards and heat. Run the tires at the pressure the owners manual recommends unless you have tires that are not stock, but never over their rating. Larry
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NoMoreRicers
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Report this Post09-08-2013 12:39 AM Click Here to See the Profile for NoMoreRicersClick Here to Email NoMoreRicersSend a Private Message to NoMoreRicersEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by trotterlg:

In any case running a tire over it's maximum rated pressure is a bad idea, you are running the front over their rating. When you do that they are more easily damage by road hazards and heat. Run the tires at the pressure the owners manual recommends unless you have tires that are not stock, but never over their rating. Larry


Just want to add in another opinion. My grandfather has ran 15-20 psi over on all of his tires for 40 years trying to get better gas mileage.
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trotterlg
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Report this Post09-08-2013 01:33 AM Click Here to See the Profile for trotterlgClick Here to Email trotterlgSend a Private Message to trotterlgEdit/Delete MessageReply w/QuoteDirect Link to This Post
There is a difference in the tire pressure that is recommended for the car and the maximum pressure printed on the side of the tire. The people who make the tire probably know how much pressure it can safely hold. Larry
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johnt671
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Report this Post09-08-2013 09:11 AM Click Here to See the Profile for johnt671Click Here to Email johnt671Send a Private Message to johnt671Edit/Delete MessageReply w/QuoteDirect Link to This Post
The owners manual or label on the door gives the tire pressure the Pontiac found to be best all around for wear and handling. The pressure on the tire gives the max pressure that the tire can safely hold. If you go over the pressure on the side wall you are over the safe pressure for that tire. As covered above that will cause wear and handling problems, and when driving the car the tires will heat up and cause the pressure to go higher. This could cause the tire to blow, or the bead to pop if it is to high.

Some people use the chalk method to find the ideal pressure for their tires, but you shouldn't go over the max pressure on the side wall. The best that will happen is excessive tire wear, the worst is massive tire failure while driving.
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Old Lar
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Report this Post09-08-2013 09:39 AM Click Here to See the Profile for Old LarSend a Private Message to Old LarEdit/Delete MessageReply w/QuoteDirect Link to This Post
If your car wanders, I'd look at suspension components.
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olejoedad
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Report this Post09-08-2013 09:46 AM Click Here to See the Profile for olejoedadClick Here to Email olejoedadSend a Private Message to olejoedadEdit/Delete MessageReply w/QuoteDirect Link to This Post
30 PSI front and rear.
Mid engine cars feel 'nervous' in a straight line due to weight distibution.
Check for worn suspension components and proper alignment.
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Tony Kania
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Report this Post09-08-2013 10:02 AM Click Here to See the Profile for Tony KaniaSend a Private Message to Tony KaniaEdit/Delete MessageReply w/QuoteDirect Link to This Post
Non daily driven Fiero...

My tire pressure is set to the outside temp, or the driving conditions. If it is 90 degrees out, I run a lower pressure. About 5 psi. When the seasons change, I run a few more pounds.

If I am planning on a spirited drive in the dry, I increase pressure before the run.
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Blacktree
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Report this Post09-08-2013 11:13 AM Click Here to See the Profile for BlacktreeClick Here to visit Blacktree's HomePageClick Here to Email BlacktreeSend a Private Message to BlacktreeEdit/Delete MessageReply w/QuoteDirect Link to This Post
Your car may be handling weird because of your mismatched tires. If the maximum tires pressures are that different, then they most likely have very different handling characteristics. If your tires are so dissimilar that they cause handling problems, then you need different tires.

Anyway, the best air pressure to run in your tires is whatever results in even wear across the tread.

[This message has been edited by Blacktree (edited 09-08-2013).]

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Tweeder
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Report this Post09-08-2013 03:35 PM Click Here to See the Profile for TweederSend a Private Message to TweederEdit/Delete MessageReply w/QuoteDirect Link to This Post
What ever the recommendation on the side of the tire, after all they made it.

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Report this Post09-08-2013 06:32 PM Click Here to See the Profile for BoostdreamerClick Here to Email BoostdreamerSend a Private Message to BoostdreamerEdit/Delete MessageReply w/QuoteDirect Link to This Post
I run 32 psi on all four corners.

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BlackEmrald
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Report this Post09-08-2013 06:59 PM Click Here to See the Profile for BlackEmraldClick Here to Email BlackEmraldSend a Private Message to BlackEmraldEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Tweeder:

What ever the recommendation on the side of the tire, after all they made it.



This is incorrect. That is the MAX pressure it is safe to run at.

I put 33 PSI in car tires and 35 in pick ups (unless they are heavy duty).

Once again, the number on the tire is MAX, not recommended. For recommended pressure, refer to the sticker in the driver door jamb.

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theogre
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Report this Post09-08-2013 08:25 PM Click Here to See the Profile for theogreClick Here to visit theogre's HomePageSend a Private Message to theogreEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by RilesOfSmiles:
My front tires are rated at 35 psi max press and my rears are 44 psi max press. I keep all 4 at 40 psi. Is this a good idea or not?

No.

Could something go wrong?
Maybe.
Front is 40 psi cold then add more pressure when heated.
Will void any warranty by over pressure.

The car seems to wander a bit if the pressure is much lower
Bad tire(s), Iffy suspension, bad cradle bushing, etc can cause this.
Mix brand/model of tires on a car won't help.

 
quote
Originally posted by BlackEmrald:
This is incorrect. That is the MAX pressure it is safe to run at.
Once again, the number on the tire is MAX, not recommended. For recommended pressure, refer to the sticker in the driver door jamb.

MAX Cold pressure it is safe to run at. Many tires leave out cold on sidewall label.
Cold means tire and rim are cold... about weather temp at the time.

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[This message has been edited by theogre (edited 09-08-2013).]

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BlackEmrald
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Report this Post09-08-2013 10:53 PM Click Here to See the Profile for BlackEmraldClick Here to Email BlackEmraldSend a Private Message to BlackEmraldEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by theogre:

MAX Cold pressure it is safe to run at. Many tires leave out cold on sidewall label.
Cold means tire and rim are cold... about weather temp at the time.


Correct as usual
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