Tire pressure and cold weather - Montana Owners Club

Ozzie · 10-10-2006, 12:56 PM

I know you guys have spent a lot of time talking about tire pressure...enough times that I know how important it is in both trucks and rigs.

We here in MN are in our fall cool down heading towards winter. We've recently gone from 70-80 degree days down to 40-50. Nights are getting close to freezing, and campgrounds are mostly shut down already. It's time to winterize after one last fling.

Ok...I was filling up my truck with fuel today and noticed my tires looked low on pressure. I pull out the guage, and my 80 pound tires are all now 55 with the onset of colder weather. Of course I filled them up, but then it hit me. What about my trailer and colder temps?
I fill it up to 80 pounds again for the weekend, colder weather keeps coming...etc. Do I need to maintain the pressure even in storage through the winter? Will this go the other way on me when the weather starts to warm again?

Glenn and Lorraine · 10-10-2006, 01:40 PM

I'm not questioning you but I do question your gage. 25 pounds is considerably more than I would expect for a change of only 30 degrees. As far as storage inflate to your normal 80 PSI and forget it. Double check them before putting it back on the road again.

BTW-You know of course you're talking about summer air and not winter air. The one thing most folks seem to forget is winterizing the tires as well as the rest of the rig. All of the old summer air should be removed and re-inflated with fresh, new winter air. To be sure you are getting true winter air wait until after December 21st before doing this winterising. True winter air has an inherent anti-freeze that will keep it in a gaseous state and prevent it from breaking down into a liquid and freezing.

LonnieB · 10-10-2006, 01:43 PM

Spoken like a true tire guy Glenn, couldn't have done it better myself.

bsmeaton · 10-10-2006, 01:47 PM

Ozzie,

That's an interesting question - I would be concerned that a warm trend and some hot sun would cause overinflation and damage the tires if I inflated them up to 80psi in the cold winter - especially if I didn't get there in time to let some air out (Monty in storage).

BTW, Dory's car has pressure sensors and they typically alarm when it sits outside below freezing. It only takes a couple of minutes of driving to silence them. Not sure what the threshold is for alarm, but there must be some variation given the temp. They always check normal with a gauge after she has been on the road.

Ozzie · 10-10-2006, 01:48 PM

You may be right about the gage...it was a backup and not a very good one. I'll have to recheck it again.

Interesting note about summer air and winter air. I never knew there was a difference.
Seeing that I just bought new wheels all around (spare too

), I think I'll be paying more attention to winter storage to make sure they are good to go. Thanks for the tips...

Glenn and Lorraine · 10-10-2006, 02:05 PM

Quote:

quote:Originally posted by bsmeaton

Ozzie,

That's an interesting question - I would be concerned that a warm trend and some hot sun would cause overinflation and damage the tires if I inflated them up to 80psi in the cold winter - especially if I didn't get there in time to let some air out (Monty in storage).

BTW, Dory's car has pressure sensors and they typically alarm when it sits outside below freezing. It only takes a couple of minutes of driving to silence them. Not sure what the threshold is for alarm, but there must be some variation given the temp. They always check normal with a gauge after she has been on the road.

Not too worry Brad. There isn't a temperature difference that could cause the kind of over inflation that could possibly do damage to a tire.

Consider this... You pull your rig onto the hiway with all tires inflated to their proper pressures. Your now traveling down the black topped hiway at 65MPH with air temps approaching 90. The sun is beating down on that black top raising the surface temps to well over 125 degrees. That inflation you had in your tires when you started out has grown considerably and with no damage being done to the tires and NO you don't lower the pressure to compensate.

That is a considerable difference with no harm being done and much more than 50 or even 75 degrees of the air temperature change can cause on a vehicle sitting stationary.

bsmeaton · 10-10-2006, 03:13 PM

Ya I guess you're right Glenn - traveling down the hot highway probably inflates a lot higher than it would just setting in the sun at storage. I guess for me I'll just make sure there at the right pressure when I park it for the season.

Brad

Mrs. CountryGuy · 10-10-2006, 04:24 PM

Glenn

You wrote:

"BTW-You know of course you're talking about summer air and not winter air. The one thing most folks seem to forget is winterizing the tires as well as the rest of the rig. All of the old summer air should be removed and re-inflated with fresh, new winter air. To be sure you are getting true winter air wait until after December 21st before doing this winterising. True winter air has an inherent anti-freeze that will keep it in a gaseous state and prevent it from breaking down into a liquid and freezing."

Carol asks, WHAT????

Geesh Glenn, I know you are the tire expert here, but this post is a bit out there for me. Could I interest you in some swamp land in Florida I have for sale???

patodonn · 10-10-2006, 04:40 PM

Yeah, but.....leaving a high altitude cold winter clime (maybe 15-20 F, e.g., Tahoe) with 80 psi tires and driving to, say Palm Springs, in one haul...won't the big ambient temp difference and hot highways cause an over pressure?? That's about a 60 degree + ambient temp change, plus the highway temps are lots higher...Seems like it would make a difference...just asking....

c5racer · 10-10-2006, 05:20 PM

I read last week where 12 degrees temperature drop equates to a 1 pound drop in pressure. It also works the other way. With my Pressure Pro I find elevation makes a difference also.

Montana Sky · 10-10-2006, 05:31 PM

I keep my tires at 80 psi during summer use as well as winter storage. So far after 2.5 years of use, the tires still read 80psi.

virgil47 · 10-11-2006, 02:10 AM

As we were traveling to Alaska this year, I noticed a fluctuation in tire pressure several times. When we left the desert and climbed into the mountains where it was cooler the tire pressure would drop as much as 3 pounds (and vice-versa). Whenever the temperature changed significantly (20-30 degrees) I would need to adjust the tire pressure, both on the trailer and the truck.

Glenn and Lorraine · 10-11-2006, 05:40 AM

Quote:

quote:Originally posted by Mrs. CountryGuy

Glenn

You wrote:

"BTW-You know of course you're talking about summer air and not winter air. The one thing most folks seem to forget is winterizing the tires as well as the rest of the rig. All of the old summer air should be removed and re-inflated with fresh, new winter air. To be sure you are getting true winter air wait until after December 21st before doing this winterising. True winter air has an inherent anti-freeze that will keep it in a gaseous state and prevent it from breaking down into a liquid and freezing."

Carol asks, WHAT????

Geesh Glenn, I know you are the tire expert here, but this post is a bit out there for me. Could I interest you in some swamp land in Florida I have for sale???

Carol?? Would I lie to you?? You didn't know about summer/winter air?? Maybe we should ask CountryGuy about this as men are more...well let's not go there.

Tell ya what I'm gonna do. I'll swap some beautiful Arizona ocean front property for that Florida swamp land. At least swamp land can be drained, filled in and built upon. This is a one time offer not to be repeated in the next...... Well maybe again tomorrow.

sreigle · 10-13-2006, 08:59 AM

As for the question asking if it is necessary to maintiain tire psi while the rig is in storage for the winter -- I am not an expert but I never worried about it so long as the tire wasn't flat or close to flat. I just checked and aired them up before the first trip in the Spring.

bsmeaton · 10-13-2006, 10:26 AM

I forgot to check my pressure when I put it in storage, guess I'll check it when I change my summer air to winter air after December 21st.

Glenn,
After I flatten the tires to get the summer air out, do I have to wrap my arms around the tires and squeeeze to get all of the air out, or is a little bit of summer air OK mixed with the winter air. Maybe I should get a vacuum pump. If I install an air ride hitch, would I need to change that air too?

Inquiring minds want to know

Brad

Mrs. CountryGuy · 10-13-2006, 11:17 AM

Brad,

Come to Michigan RIGHT NOW! We got winter air at this very moment and the wind chills to help you get all that summer air out of those tires!!

Cat320 · 10-13-2006, 02:46 PM

Also, your tire pressure will not read correctly unless you have a winter guage for the winter air and a summer guage for the summer air. They have there own weights and pressures based on the temperature/atmospheric pressure/humidity/density altitude/dew point.

Glenn and Lorraine · 10-13-2006, 03:23 PM

WHEW!!! Thanks Bert, I don't know how I could have forgotten that winter gauge summer gauge thing. Without the proper gauge your pressures could be off by as much a 40%.
Thanks Bert for bringing that up.

MAMalody · 10-13-2006, 07:44 PM

I hate to ask a serious question, but, are those colored pressure stems really any good. I now check my air at the first of every day when I am on the roadm, however, it would be nice to be lazy...I understand they are set to change color after a 10# decrease in psi...that would be 12.5% for an 80# tire...that seems quite a swing.

LonnieB · 10-14-2006, 02:41 AM

Hello Mike, I don't think the stems with the indicators are really intended to take the place of cheking your pressure with a guage. I do think they are a very good indicator of pressure loss between the times you manually check your tires. For example, while traveling, each time you stop you can simply walk around the rig to make sure they are all green, and if one is not you know you have a problem. Without the indicator stems, you may have a leak slow enough that it is not noticeable, get back on the road and ruin a tire or have a blowout, and risk much more. My answer to the question is, I would still check pressure at the start of each day with a GOOD manual or digital guage.

You may also like: