PSA: Tire pressure in cold weather

[mildone]

Our house is 71-72F every minute of every year, as the wife likes it that temp, even if that means heat in the mornings and AC in the afternoons on fall/spring days, lol. I'm sure our bills are ridiculous. Maybe if we had sheep we could at least save on the heating bill.

With sheep, you can save on the wife bill.

Please don’t tell her I said that. 🙏

 

[RutgersLifeR]

I fill my tires with a proprietary blend of laughing gas and vaporized cocaine. More smiles per mile while going even faster.

Can I ask where you get your tires serviced with this? I'm hoping too it's in Monmouth county.

 

[DJ Spanky]

Can I ask where you get your tires serviced with this? I'm hoping too it's in Monmouth county.

He gets serviced by a proprietary blend of hookers, pimps, Columbians and sheep.

 

[mildone]

Can I ask where you get your tires serviced with this? I'm hoping too it's in Monmouth county.

Nobody sells it. But I have a recipe...

Get the laughing gas from your dentist, the blow from your local neighborhood dealer. The vaporizer you want to get secondhand from a nearby pharmaceutical lab, or it’ll be very expensive.

Take a wheel off the car, fully deflate it, bring it in the house to experiment.

Then play around with the mix ratio till you find one that doesn’t kill you instantly. I recommend 99999 parts to 1 to start with. I got killed instantly a few times but eventually I got it right.

Best thing is, if you get a breakdown, you can get out an air hose and in minutes you won't even care that you're stuck on the side of a highway with no shoulder as cars whiz past at 80mph or more. Pro hint: put the air hose away before the cops show up, and don't focus too much on one tire or you'll get a flat.

 

[mildone]

He gets serviced by a proprietary blend of hookers, pimps, Columbians and sheep.

I mean, yes. But that's a different sort of servicing.

 

[wheezer]

Well that probably increased exit pressure, but I'm not sure if that helped your tire pressure.

Gas pressure

 

[mildone]

Gas pressure

...is why God invented beans.

 

[RutgersRaRa]

Ok Spanky.
So the important thing is to add when temps are freezing.
Question:
I was at 35 on thanksgiving, at 30 now.
If i fill to 35 immediately, what would happen if it was 60 on Thursday?

 

[mildone]

Is what I'm talking about. Killed instantly 'cause he got his mix all wrong.

 

[iReC89]

Inspired by this thread I stopped to get air yesterday and there was a calm but curious police officer asking the unfazed young driver of the car at the air pump next to me if he noticed his tire was missing. Kid said no. All that was left was the rim and some shreds of rubber. Also some rear corner bumper damage. I shamefully did not take a picture of this scene.

 

[RU848789]

With sheep, you can save on the wife bill.

Please don’t tell her I said that. 🙏

I told her. She said, FU, I thought you were my friend.

 

[29PAS]

Yes, the Brunswick Formation (now known as the Passaic Formation) which is heavily sedimentary/shale-containing, is common to much of CNJ/NNJ, especially in the Raritan Valley, owes its reddish hue to the presence of hematite, a mineral formed from oxidized iron (hematite and hemoglobin both contain the Greek root "haima" meaning blood); iirc, most of Monmouth County and the SNJ coastal plain has mostly sandy soils. I'm not a geology expert - need 4Real for this one.

Maybe we should discuss Antomology, the study of ants, next (old joke - actually knew someone who thought that).

https://en.wikipedia.org/wiki/Geology_of_New_Jersey

We called that red stuff "New Brunswick Shale" back in the '60's. I lived in Davidson freshman year and when it rained, everybody's shoes were covered with that crap.

 

[Bagarocks]

Wait ya hafta check yer tire pressure?
I thought thats what that little thingy was for, ya know the one that lights up in yellow in the dashboard.

 

[Yeah Baby]

see my post, although if you're tired of answering that question, but don't know the answer, what, exactly are you telling people? 😉

Zap caught the joke.

 

[DJ Spanky]

Tommy, Tommy, Tommy, why do you keep reporting my thread?

 

[AreYouNUTS]

Tommy, Tommy, Tommy, why do you keep reporting my thread?

Why is this thread being "reported?" Someone must have ZERO life I guess lol! Probably should FOCUS on more important things, right?

 

[mildone]

Tommy, Tommy, Tommy, why do you keep reporting my thread?

Is Tommy the troll of many names?

 

[RCBeta79]

The rough rule of thumb for ideal gases, like air (or nitrogen, which is very similar to air which is about 78% nitrogen and 21% oxygen), which follow the PV=nRT relationship, is for every 10C change in temp, there is a 3.7% change in pressure (or for every 10F change in temp there is a ~2% change in pressure), as calculated from Gay-Lussac's Law for ideal gases (in a fixed volume, closed system, like a tire), which says that P1T1 = P2T2, where temperature is absolute temperature (in Kelvin). Specifically (solving for P2 when the temp has changed), at 0C, which is 273K, if one has ~30 psi tire pressure and the temperature goes up to 10C (or 283K or 50F), then the pressure will go up 3.7% (283K/273K - the calc has to use Kelvin) to about 31.1 psi and similarly if the temperature drops to -10C (or263K or 14F), the tire pressure will go down 3.7% to about 28.9 psi.

So within a season where temp usually doesn't vary more than +/-10C (like 14-50F in winter in these parts), there's really little reason to adjust one's tire pressure if one has been doing so periodically through the year. However, if the last time one adjusted the tire pressure was in summer, say at 40C (102F) on the hottest day of the year, then at 0C, months later, that pressure would've dropped about 14.8% or 4.4 psi to 25.6 psi if it was 30 psi at 40C/104F.

So @DJ Spanky is absolutely correct that one probably has lost 2-6 psi pressure if one hasn't adjusted the tire pressure since it was fairly warm out and one should adjust their tire pressure now. If one adjusts tire pressure 3-4 times a year or more (especially if one has a slow leak), then that's likely all one ever needs to do. Just thought I'd share the science of it all.

@zappaa - going from 32F (0C/273K) to 60F (16C/289K) will raise the tire pressure by 5.9% (289/273) or about 1.8 psi if originally at 30 psi and typically, less than 2-3 psi difference in either direction isn't going to be a major issue for performance.

Lastly, nitrogen for tires is a giant scam. Air is already 78% nitrogen (almost all of the rest is 21% oxygen and "nitrogen" for tires is usually only about 95% nitrogen, not 100%) and most of the purported advantages are complete BS. There is a very slight advantage in maintaining tire pressure, over a month or more, but certainly not worth the cost, especially since it's pretty simple to top off tire pressure every month or two with free air. See the link below.

https://www.edmunds.com/car-maintenance/should-you-fill-your-cars-tires-with-nitrogen.html

Thanks Professor! You are an expert in weather, Rutgers football and science. Much appreciated.

The Tire Pressure Low indicator on my Subaru Outback came on a few days ago.
I checked the tire pressure on all four tires and needed to fill them all.

I have a portable Ryobi unit (with universal battery for leaf blowers, etc.) that is easy to use....and would recommend keeping one in your car, especially during winter.

 

[RU848789]

Thanks Professor! You are an expert in weather, Rutgers football and science. Much appreciated.

The Tire Pressure Low indicator on my Subaru Outback came on a few days ago.
I checked the tire pressure on all four tires and needed to fill them all.

I have a portable Ryobi unit (with universal battery for leaf blowers, etc.) that is easy to use....and would recommend keeping one in your car, especially during winter.

Thanks! And thanks for the intel on the Ryobi - been debating getting one, since it's annoying when I find an air-station that's broken or charges quarters and I don't have any "regular" gas station, as I'm all over NJ.

 

[DJ Spanky]

I have a portable Ryobi unit (with universal battery for leaf blowers, etc.) that is easy to use....and would recommend keeping one in your car, especially during winter.

I have a portable Craftsman which plugs into my cigarette lighter which has worked great for years. Wish I could get another one for my son's car.

 

[fsg2]

I have a portable Craftsman which plugs into my cigarette lighter which has worked great for years. Wish I could get another one for my son's car.

Can't you?

Seeing 12-V Craftsman air compressors available. Maybe not the same model, though.

 

[DJ Spanky]

Can't you?

Seeing 12-V Craftsman air compressors available. Maybe not the same model, though.

I didn't think those Craftsman tools were even made any more, where'd you see them?

 

[ashokan]

Thanks Professor! You are an expert in weather, Rutgers football and science. Much appreciated.

The Tire Pressure Low indicator on my Subaru Outback came on a few days ago.
I checked the tire pressure on all four tires and needed to fill them all.

I have a portable Ryobi unit (with universal battery for leaf blowers, etc.) that is easy to use....and would recommend keeping one in your car, especially during winter.

My battery-pack jumper starter came with a 4x4 compressor that actually works well.
Project Farm on YouTube (hottest tool channel going at the moment) just did a nice review of battery packs and the inflators some come with

 

[fsg2]

I didn't think those Craftsman tools were even made any more, where'd you see them?

Did a quick Google of "12-V Craftsman air compressor". Amazon had one or two styles and other links came up.

Was just curious if they stopped making them

 

[mildone]

Thanks Professor! You are an expert in weather, Rutgers football and science. Much appreciated.

The Tire Pressure Low indicator on my Subaru Outback came on a few days ago.
I checked the tire pressure on all four tires and needed to fill them all.

I have a portable Ryobi unit (with universal battery for leaf blowers, etc.) that is easy to use....and would recommend keeping one in your car, especially during winter.

I keep a Milwaukee M18 version of the same thing. Always good to have a pump in case tires run low.

 

[bethlehemfan]

You can buy very serviceable digital pumps for less than $30 on amazon.

 

[iReC89]

Thanks Professor! You are an expert in weather, Rutgers football and science. Much appreciated.

The Tire Pressure Low indicator on my Subaru Outback came on a few days ago.
I checked the tire pressure on all four tires and needed to fill them all.

I have a portable Ryobi unit (with universal battery for leaf blowers, etc.) that is easy to use....and would recommend keeping one in your car, especially during winter.

I don’t see a 48v Ryobi compressor, unfortunately. Would have been nice to use those batteries.

I have had those jump/start compressors in the past but honestly now I just keep a bike pump in the trunk and it does the job. The last air station let more out then it put in and I had to use it. Looks pathetic but gets the job done .

My fav tool for this though is a decent digital pressure gauge with a small flashlight on it.