New Tires - What Air Pressure to Run?

Discussion on wheel & tire issues
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jpalmer
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Location: Morgantown, WV

New Tires - What Air Pressure to Run?

Post by jpalmer » Tue Sep 17, 2019 2:19 am

So at 25K miles my Goodyear RSA's gave up. Not wanting to spend $200+ per tire for a new set of subpar tires (IMHO). So I started looking for something else. I found a Continental Purecontact LS in 245/50/18's with a V100 rating (100lbs more load per tire - .3" taller & .2" wider), speed rated at 149mph and $205 per tire mounted & balanced.. The issue that I didn't think about is that the old tires had a max pressure of 44 psi, these new tires are 51 psi. I don't want to run too much pressure for fear of tripping the TPMS on the high side, but I am afraid that if I don't run enough pressure I will degrade the life of the new tires. I am running 40 psi all around right now.

Any thoughts on this?
As always thanks,
Jeff

1996 Caprice LT1 B4U - Sold - So long my friend - it was a great 17 years!
2001 Silverado LS 3500 DuraMax Dually 4x4
2004 Suburban 2500 6.0L 4x4
2013 Caprice PPV 6.0L

s/c'd cav
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Re: New Tires - What Air Pressure to Run?

Post by s/c'd cav » Tue Sep 17, 2019 4:16 pm

what the sticker says

Navy Lifer
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Re: New Tires - What Air Pressure to Run?

Post by Navy Lifer » Wed Sep 18, 2019 12:21 am

Jeff,

What year is your car, out of curiosity?

I've addressed this before, in regards to TPMS sensitivity. By the way, I don't think there is a "HIGH" alarm or limit in the TPMS itself.

The reason I asked about model year is a matter of information in the Owner's Manual.

There is a section in the OM about tire pressure (only for 2011 model year as far as I know) that provides guidance to run 36 PSI, same as SS & G8 (not 100% on that) on all 4 corners--with the stipulation that this pressure does not meet requirements for "high speed/full load" conditions.

Another thing with running 36 PSI is that ambient temp fluctuations using that pressure setting (36 PSI COLD) may result in pressure transients in cold weather that result in nuisance alarms.

I run 36 PSI and find it much more forgiving as far as ride, but I'm also using SS springs. The TPMS issue was resolved by working with my local dealer tech to make an adjustment to the RCDLR/TPMS low pressure alarm threshold, so that low ambient temp pressure excursions below the factory-set alarm don't exist in my case, even though TPMS still functions to advise me when a tire is actually low--maybe 26-28 PSI, still totally safe. It has served me well.

The issue can be that some techs don't know how to do this, that it requires a Tech tool, and/or that dealers think it's not a system they can make any changes to without creating some sort of liability for the dealership. It's quick and should not cost much, but that's the other issue--never know what a guy with a Tech tool is going to want to do this, or how strong the owner's desire is to avoid any dealer contact.

There's a thread here that gives a more complete rundown of this topic--several, in fact.

Pg 3 of the thread
https://www.newcaprice.com/forum/viewto ... 1&start=20

Start reading at about this post
https://www.newcaprice.com/forum/viewto ... stem#p2823

OM quoted - removed from later years, although there was no change to tire specs
https://www.newcaprice.com/forum/viewto ... t=50#p5734

cerbomark
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Re: New Tires - What Air Pressure to Run?

Post by cerbomark » Wed Sep 18, 2019 1:21 pm

35-36 will give you a nice ride and should wear well too.
2016 C1

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jpalmer
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Location: Morgantown, WV

Re: New Tires - What Air Pressure to Run?

Post by jpalmer » Mon Sep 23, 2019 3:29 am

I have a 2013 9C1(25K miles), the sticker on the door jam says 39 PSI front 44 PSI rear, but that is for the RS-A's W rated and a load range of 1604 lbs per tire. These tires are 1704 lbs per tire and are V rated (149 mph). I just wanted to make sure I am running enough pressure for even tire wear and that if I take a quick jaunt to triple digits the air pressure is adequate for the speed and heat.

At the current 40 psi the ride is not bad at all, and these tires are quiet. Reading Bill's posted threads now....
Jeff

1996 Caprice LT1 B4U - Sold - So long my friend - it was a great 17 years!
2001 Silverado LS 3500 DuraMax Dually 4x4
2004 Suburban 2500 6.0L 4x4
2013 Caprice PPV 6.0L

Navy Lifer
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Re: New Tires - What Air Pressure to Run?

Post by Navy Lifer » Mon Sep 23, 2019 1:56 pm

my only purpose was to clarify that IF the TPMS settings are lowered, it eliminates potential nuisance alarms if running lower pressures than the door sticker recommendations. I felt comfortable and justified in changing the settings, knowing the Owner's Manual (2011) addresses the lower pressure setting (36 PSI), and that other Holden sedans use standard pressures lower than PPV.

My car was never in service (as a cop car), does not carry the potential load that calls for the higher pressures, and the car is fitted with SS springs.

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jpalmer
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Re: New Tires - What Air Pressure to Run?

Post by jpalmer » Wed Oct 16, 2019 1:02 am

Well, had a cold snap come through over the weekend and when I went to work this morning I noticed that air pressure dropped to 34 psi. To my surprise no alarms or warnings from TPMS. Go figure.
Jeff

1996 Caprice LT1 B4U - Sold - So long my friend - it was a great 17 years!
2001 Silverado LS 3500 DuraMax Dually 4x4
2004 Suburban 2500 6.0L 4x4
2013 Caprice PPV 6.0L

kevink
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Re: New Tires - What Air Pressure to Run?

Post by kevink » Wed Oct 16, 2019 3:01 am

I used to keep mine at 34 psi all the time and never get alarms unless it got really cold and it dropped below that. If you keep them at 34 psi, you should be good. At least that's been my experience.

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