CHECK YOUR TIRE PRESSURE!

[borgward]

And the formula is...

That's what I don't remember. Back then people were beginning to inflate with nitrogen because it was supposed to be stable regardless of temperature rise or drop.

 

[George Bynum]

That's what I don't remember. Back then people were beginning to inflate with nitrogen because it was supposed to be stable regardless of temperature rise or drop.

It makes the nitrogen supplier money. What's important is that the compressed gas is dry. Our air is 99% nitrogen and oxygen; each obey the same gas law within experimental error.

 

[borgward]

Major constituents of air, by mole fraction[8]

notes: (A) Mole fraction is sometimes referred to as volume fraction; these are identical for an ideal gas only. (B) ppm: parts per million by molecular count The total ppm above adds up to more than 1 million (currently 83.43 above it) due to experimental error. (C) The concentration of CO2 has been increasing in recent decades (D) Water vapor is about 0.25% by mass over full atmosphere (E) Water vapor varies significantly locally[11]
If air is not dry:
Name	Formula	in ppm(B)	in %
Gas	Mole fraction(A)
Dry air
Nitrogen​	N2	780,840	78.084
Oxygen​	O2	209,460	20.946
Argon​	Ar	9,340	0.9340
Carbon dioxide (April 2022)(C)[13]​	CO2	417	0.0417
Neon​	Ne	18.18	0.001818
Helium​	He	5.24	0.000524
Methane​	CH4	1.87	0.000187
Krypton​	Kr	1.14	0.000114
Water vapor(D)​	H2O	0–30,000(D)	0–3%(E)

 

[totegoat]

Checked psi with 5 gauges, 4 of them read the same. Threw the odd one away.

 

[buster]

OE tire pressure for the ZR2 is 35psi. I put 40psi in a few weeks back after coming off the beach. I left it at that. Due to the temperature fluctuations, my cold PSI is now around 36-37psi.

 

[mdocod]

Swapped to my "winter" tires on the H3 last night after thanksgiving festivities as the snow started to fall.

Door Sticker: 35PSI for 285/75R16 LT because 35PSI is the "minimum" for LT tires and universe ending paradox occurs below 35PSI... or something...

I run 315/75R16, which, at 35PSI would carry a 10K lb truck. I adjust/set pressures regularly depending on what the vehicle is being used for:

33-38PSI: Sustained highway travel at ~75MPH. Safe road trip pressure for hot weather.
28-32PSI: Fair and wet weather daily driver for shorter trips and mixed driving, occasional highway use.
15-20PSI: Cold weather with expected snowpack/ice or unplowed snow up to ~8" depth. ~45-60MPH Max.
11-14PSI: Fair/Hot weather offroad, rocks, washboards and cold weather with 8-16" of unplowed snow expected on roads, up to ~30-40mph max.
8-10PSI: Fair/Hot weather bottomless sand. Cold weather and unplowed snow measured in feet, up to 20-30mph.

Snowpack/ice on roads today so I set 19PSI front and 17PSI rear. Good results.

 

[cptbarkey]

The Milwaukee M18 inflater is a wonder of engineering. Will have no excuse to keep all of the fleet aired up at all times. What was annoying now takes a fraction of the time. Connect, hit buttons, wait 30 seconds to a minute, hit a button, reconnect, rinse repeat.

 

[Sequoiasoon]

The Milwaukee M18 inflater is a wonder of engineering. Will have no excuse to keep all of the fleet aired up at all times. What was annoying now takes a fraction of the time. Connect, hit buttons, wait 30 seconds to a minute, hit a button, reconnect, rinse repeat.

How noisy is the M18 inflator? Think quiet Sunday morning, family not awake yet, which is when I often check and top off 5-6 vehicles.

I have M18 batteries as I use it for my impact gun and pole saw. Just not sure if I need another inflator but quiet and portable is always nice.

I have 2-3 older compressors that I might actually toss out as they are old, heavy, noisy and really just in the way. I hate to toss out working stuff but need to curb the hoarding habits for stuff I'm not using.

 

[Sequoiasoon]

Swapped to my "winter" tires on the H3 last night after thanksgiving festivities as the snow started to fall.

Door Sticker: 35PSI for 285/75R16 LT because 35PSI is the "minimum" for LT tires and universe ending paradox occurs below 35PSI... or something...

I run 315/75R16, which, at 35PSI would carry a 10K lb truck. I adjust/set pressures regularly depending on what the vehicle is being used for:

33-38PSI: Sustained highway travel at ~75MPH. Safe road trip pressure for hot weather.
28-32PSI: Fair and wet weather daily driver for shorter trips and mixed driving, occasional highway use.
15-20PSI: Cold weather with expected snowpack/ice or unplowed snow up to ~8" depth. ~45-60MPH Max.
11-14PSI: Fair/Hot weather offroad, rocks, washboards and cold weather with 8-16" of unplowed snow expected on roads, up to ~30-40mph max.
8-10PSI: Fair/Hot weather bottomless sand. Cold weather and unplowed snow measured in feet, up to 20-30mph.

Snowpack/ice on roads today so I set 19PSI front and 17PSI rear. Good results.

I'm glad it all works for you. The only time I air down is if I'm at the beach. I don't do much other off road.

H3 is not a light weight vehicle and should be aired for correct load carrying capacity. LT tires normally need more. At the low pressures you are generating more heat and wear to the tire structure from all I have learned.

Check with @CapriRacer 's website http://www.barrystiretech.com/ and then the load tables.

 

[We're Metals]

Dont forget your spare tire!


I checked both of mine and the first one was completely flat (2010 Civic) and the other was at 18 PSI (2020 Rav4).

 

[SHOZ]

I'll throw one in to this as well. If you have a Space Saver spare, it's supposed to be 60 psi. If you don't check it every oil change it won't be anywhere close to that.

I've tried metal valve caps, replacing the valve core, nothing helps other than checking and inflating.

And be sure to check the tire itself too. Found this after about 7 years in the trunk.

 

[Ragingbull99]

Once a week in the winter.

 

[The motor guy]

Hello, GOOD ADVICE except
1) People are frequently sooooooo lazy
2) "I can't be baaaaaathuurd"
3) "I never did that before!"
4) "I'm a brain surgeon, my tires don't loose air."
Kira

10psi? Usually they come on when only like 3 psi low hence why it's just another idiot light in the dash that gets ignored

 

[borgward]

Comes on at 10psi low on both our Fords.

 

[bullwinkle]

That's what I don't remember. Back then people were beginning to inflate with nitrogen because it was supposed to be stable regardless of temperature rise or drop.

ALL gases lose pressure with a drop in temperature. The Combined Gas Law. Nitrogen has an advantage in that it doesn’t leak as quickly, and as a noble gas, will not react chemically with rubber, steel, etc. I will usually go a little high at the air hose, then check them the next morning & adjust them down if necessary. I’ve seen the rears go over 90 on the Transit on a long, hot summer Interstate run. Next morning they’re right back down to 75!

 

[silveravant]

I would say that if your tires are increasing from 75 to 90 lbs that they are overloaded. Check out barrystiretech.com. and read the pressure buildup test article.

 

[RooflessVW]

I wish there were more react emojis

 

[John105]

ALL gases lose pressure with a drop in temperature. The Combined Gas Law. Nitrogen has an advantage in that it doesn’t leak as quickly, and as a noble gas, will not react chemically with rubber, steel, etc. I will usually go a little high at the air hose, then check them the next morning & adjust them down if necessary. I’ve seen the rears go over 90 on the Transit on a long, hot summer Interstate run. Next morning they’re right back down to 75!

Great minds think alike. Since I do the Costco nitrogen I too overinflate by maybe 3-4 psi. And check next morning and let some out. Why? It’s already hot when I’m there. Also I can’t add nitrogen at home.

I get it there’s not a huge benefit to nitrogen but it’s free. Maybe it takes longer to pass through the sidewall.

 

[72C10]

I would say that if your tires are increasing from 75 to 90 lbs that they are overloaded. Check out barrystiretech.com. and read the pressure buildup test article.

That is a great site. Thanks for posting.