Cold temp droped tire pressure 7lbs

nickfromny · 10-10-2008, 11:18 AM

Presure back up to 42f/40r and mph is back up over 50mpg. Winter is comming.

Sheepdog · 10-10-2008, 12:32 PM

yet another reason to think about Nitrogen. My Tire pressure is exactly what it was when filled. 42/40. 10K miles now not a single pound difference than when set.

Neicy · 10-11-2008, 10:02 AM

Quote:

Originally Posted by nickfromny

Winter is comming.

DaveinOlyWA · 10-11-2008, 11:21 AM

TP is something you should check on a weekly basis no matter what the season

jdenenberg · 10-11-2008, 11:51 AM

Ignoring the possibility of a leak, PSI is guaranteed to drop as air temperature drops.

Warning Tech Alert - The relevant formula is P*V=N*R*T where T is absolute temperature (P is Pressure, V is Volume, N*R is the amount of air in the tire). So a 50 degree drop in temperature results in approximately a 10% (4 PSI) drop with dry air (or nitrogen - no difference). Moisture in your tires can cause a slightly higher drop in PSI. (sorry, I'm an engineering professor and can't help myself)

JeffD

richard schumacher · 10-11-2008, 01:31 PM

Quote:

Originally Posted by Sheepdog

yet another reason to think about Nitrogen. My Tire pressure is exactly what it was when filled. 42/40. 10K miles now not a single pound difference than when set.

That means (1) whoever mounted the tires did a good job, and (2) the tire temperatures were the same at the two measurements. The nitrogen fill had nothing to do with it other than being a relatively dry and inert gas; air, argon, or sulfur hexafluoride would have worked just as well :_>

Codyroo · 10-12-2008, 12:10 AM

Quote:

Originally Posted by richard schumacher

.... sulfur hexafluoride would have worked just as well :_>

Man! Don't let the cat out of the bag with that one! If everyone finds out about it.....then they'll all want it......

Nothing to see here....keep moving....

richard schumacher · 10-12-2008, 03:45 PM

Quote:

Originally Posted by Codyroo

Man! Don't let the cat out of the bag with that one! If everyone finds out about it.....then they'll all want it......

They can clamor all they want, but it's an extremely efficient greenhouse gas so it will never be legal for tires.

N3FOL · 10-19-2008, 09:33 AM

This time of the year, I check my tire pressure every 1.5 weeks not longer than 2 weeks. Only a couple of my tires are dead on the spot where I want it to be...and I add just a little air on the rest. Keep it this way and your tires will last longer too. I am a little over 14K now and tires still look great.

qbee42 · 10-19-2008, 01:38 PM

Quote:

Originally Posted by richard schumacher

That means (1) whoever mounted the tires did a good job, and (2) the tire temperatures were the same at the two measurements. The nitrogen fill had nothing to do with it other than being a relatively dry and inert gas; air, argon, or sulfur hexafluoride would have worked just as well :_>

+1. Living in a warm climate does have some advantages, other than big bugs.

Tom

10-10-2008, 11:18 AM	#1
nickfromny Senior Member Join Date: May 2007 Location: Endwell, NY Posts: 101 My Car: 2009 Prius Model: Package: #3 Touring Thanks: 0 Thanked 0 Times in 0 Posts Friends: 0	Cold temp droped tire pressure 7lbs Presure back up to 42f/40r and mph is back up over 50mpg. Winter is comming.

10-10-2008, 12:32 PM	#2
Sheepdog C'Mere Sheepie! Join Date: Mar 2008 Location: Sanford FLorida Posts: 1,050 My Car: 2008 Prius Model: Package: #2 Thanks: 0 Thanked 0 Times in 0 Posts Friends: 6	Re: Cold temp droped tire pressure 7lbs yet another reason to think about Nitrogen. My Tire pressure is exactly what it was when filled. 42/40. 10K miles now not a single pound difference than when set.

10-11-2008, 11:21 AM	#4
DaveinOlyWA 3rd Time was Solariffic!! Join Date: Apr 2004 Location: South Puget Sound, WA Posts: 12,392 My Car: 2010 Prius Model: IV Package: Solar Roof Thanks: 24 Thanked 122 Times in 104 Posts Friends: 10	Re: Cold temp droped tire pressure 7lbs TP is something you should check on a weekly basis no matter what the season

10-11-2008, 11:51 AM	#5
jdenenberg Senior Member Join Date: Nov 2005 Location: Trumbull, CT Posts: 512 My Car: 2004 Prius Model: Package: Base Thanks: 0 Thanked 21 Times in 14 Posts Friends: 10	Re: Cold temp droped tire pressure 7lbs Ignoring the possibility of a leak, PSI is guaranteed to drop as air temperature drops. Warning Tech Alert - The relevant formula is PV=NRT where T is absolute temperature (P is Pressure, V is Volume, NR is the amount of air in the tire). So a 50 degree drop in temperature results in approximately a 10% (4 PSI) drop with dry air (or nitrogen - no difference). Moisture in your tires can cause a slightly higher drop in PSI. (sorry, I'm an engineering professor and can't help myself) JeffD Last edited by jdenenberg; 10-11-2008 at 02:50 PM.

10-19-2008, 09:33 AM	#9
N3FOL Senior Member Join Date: Dec 2007 Location: Stewartstown, PA. Posts: 791 My Car: 2008 Prius Model: Package: #4 Thanks: 0 Thanked 0 Times in 0 Posts Friends: 0	Re: Cold temp droped tire pressure 7lbs This time of the year, I check my tire pressure every 1.5 weeks not longer than 2 weeks. Only a couple of my tires are dead on the spot where I want it to be...and I add just a little air on the rest. Keep it this way and your tires will last longer too. I am a little over 14K now and tires still look great.

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