Check and verify your tire pressure.

[Ncasini]

I saw that my tire pressure was 4-5 psi low when the temperature dropped. After adding air to the recommended pressure, my efficiency went up. Still not as much as summer driving but an increase.
just have to watch for warmer weather and adjust it accordingly. I didn’t think it would be that much of an improvement on efficiency.
make sure to check when it’s cold and no sunlight hitting the tires.

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[SpaceEVDriver]

IMO, we should be checking tire pressure (with a real, high-quality pressure gauge) once a month and adjusting as necessary to fit the conditions.

This Toyota TSB has one of the best procedures I've seen for adjusting according to temperature of the tires, the temperature where the tire pressure is being checked, and the lowest expected ambient outside temperature for the upcoming several weeks.

https://static.nhtsa.gov/odi/tsbs/2014/MC-10133726-9999.pdf

 

[broncoaz]

Great reminder for this time of year. I checked the pressure on my 2001 Ford Expedition the other day before making a run to the dump after not driving it since October. The fronts were at 22.5 and the rear were at 28. Recommended pressures are 30 front 35 rear. I had been out of town for November and my wife was driving it like that. She did check and top off the tires on her Tesla.

 

[TonyCO]

IMO, we should be checking tire pressure (with a real, high-quality pressure gauge) once a month and adjusting as necessary to fit the conditions.

This Toyota TSB has one of the best procedures I've seen for adjusting according to temperature of the tires, the temperature where the tire pressure is being checked, and the lowest expected ambient outside temperature for the upcoming several weeks.

https://static.nhtsa.gov/odi/tsbs/2014/MC-10133726-9999.pdf

Thank you for the chart. Forgive me if this a dumb question, but would it be reasonable to expect the same pressure in all three examples? I realize they are close, but I was thinking the equations should get you to the exact pressure?

 

[JayTodd]

Nitrogen, no more fluctuations

 

[PAndaemonium]

Nitrogen, no more fluctuations

Waste of money

 

[RickLightning]

I saw that my tire pressure was 4-5 psi low when the temperature dropped. After adding air to the recommended pressure, my efficiency went up. Still not as much as summer driving but an increase.
just have to watch for warmer weather and adjust it accordingly. I didn’t think it would be that much of an improvement on efficiency.
make sure to check when it’s cold and no sunlight hitting the tires.

That's why you check MONTHLY. Raise, or lower, as needed. And before a big trip.

 

[PJnc284]

Nitrogen, no more fluctuations

lol. Air is ~80% nitrogen. My Ram supposedly came with nitrogen filled tires which I refused to pay for and I swear they seem to fluctuate more than regular air filled tires.

 

[DatOleMan]

lol. Air is ~80% nitrogen. My Ram supposedly came with nitrogen filled tires which I refused to pay for and I swear they seem to fluctuate more than regular air filled tires.

Yes, oxygen is 80% nitrogen but not 100% nitrogen. Nitrogen is an inert gas that displaces less denser gases like oxygen that creates moisture. Moisture is what heats a tire…. Remember oxygen adds fuel to a fire… nitrogen extinguish fire.
Argon is the best but too expensive for a non industrial application. Aircraft tire are inflated with argon.

 

[Mach Turtle]

Sorry if I'm being overly pedantic, or maybe I'm just taking some bait...but I feel the need to try to correct a few misconceptions which people have (usually for good reasons, such as a lack of more accurate sources of information than salespeople).

Nitrogen has a lower atomic number than oxygen (each atom is lighter) and oxygen tends to be more dense (but the difference is small). Nitrogen is a less reactive gas than oxygen, but it's not fully inert as is argon. Heck, get air too hot (such as in a VW diesel's cylinders ) and you get oxides of nitrogen, including a type of brown smog. It's possible that the rubber in a warm tire will oxidize a bit in the presence of air and less with pure nitrogen, but this is only likely to matter much if you're planning on keeping your tires for 15-20 years or more. I did that once and the sidewalls rotted out, possibly due partly to oxidation...from the outside, though, so nitrogen inside wouldn't have saved my tires.

As for moisture heating a tire, any such effect is negligible. Tires are mostly heated by friction with the ground and internal friction due to flexing when moving; they're heated by sunlight when sitting in a parking lot (TPMS or a gauge often shows the effect). And if fire is a concern for your tires in any way, the gas in your tires is the last thing about which to be concerned...

I personally don't bother with putting nitrogen in my tires; there are slight benefits but I find it more important to be able to just grab a bike pump and tweak the pressure anytime I like. Having the right pressure is a whole lot more important than the composition of the gas in there.

Argon in (some) aircraft tires? I hadn't heard that before, but it's an interesting idea. The thermal conductivity of argon is less than that of air, which would seem to be a disadvantage (less cooling of the tires from the inside), and it's denser than air which would make tires a tiny bit heavier...but not enough to matter. I'll bet many of the welders in the group know about the advantages of argon.

 

[Scorpio3d]

I generally purchase my tires from Costco, which includes nitrogen fill, Never really had much loss with the nitrogen so I think it works, personally. Still on my first set in the Lightning and I am constantly having to adjust pressure, i.e. regular air, not nitrogen!

 

[Henry Ford]

Argon in (some) aircraft tires?

No. Nitrogen works just fine.

Nitrogen seems like overkill in a modern vehicle with reasonably accurate individual TPMS sensor. Your mileage may vary.

 

[Firn]

Relevant link



Tldw; Jaco Digital

 

[Heliian]

Nitrogen, no more fluctuations

It still fluctuates, just a little less.

Aircraft tire are inflated with argon.

All of the aircraft I have worked on use nitrogen. The reason being the immense heat differential from cold to touchdown. We still need to adjust it for colder or warmer ambiant temps.

I live in a place where the summer temps can be 30degC+ and the winter -35degC. I adjust my tires as needed. Averaging about every 10degC change.

This is why I'm switching to Lt tires next. I can let them get higher pressures over my current max 45psi(cold) tires.

Ideally your tires are always at the recommended pressure cold. Also, as you load up the weight on the tires you want to add more pressure to maintain the shape of the tire.

 

[inchman254]

The Toyota document referenced above has got some great information but the examples are pretty confusing, especially since they use decimals and weird target temperatures and pressures ... probably due to C/F and psi/kpa conversion.

All gases change pressure at exactly the same rate vs temperature change. PV=nRT. n and R are constants so the only effect is PV = T. since we are talking about pressure, P = T/V. If the temperature goes down, the pressure will go down. But the temperature here, of course, is K, not F, so you don't lose all of your pressure because the temperature drops to 0 F.

Bottom line is that, regardless if you fill your tires with air, nitrogen or gaseous gold, you will lose 0.8 psi per every 10 degree (F) temperature change. Since recommended pressures are COLD pressures in your driving environment, if your truck has been sitting overnight in your nice warm shop/garage at 60F and will be driving on the road at 0F, you should add 6*0.8 =~5psi over the recommended cold pressure before leaving.

An easier rule of thumb is 1 psi per 10 F of temperature change. Better to be 1 psi high than 5 psi low.

For us Celsius fans it's 1.5psi per 10 C. I'll let you work out the kilopascals if you use 'em.

If the tires are already at the driving environment temperature (truck has been sitting outside), just fill 'em to the recommended pressure.

If you've been driving for an hour at highway speeds, add 4psi to the recommended pressure. (But, of course, you wouldn't be making any temperature corrections here because the tires are already in the driving environment)

Don't use the TPMS for filling your tires if you're using these methods ... use an accurate tire pressure gauge. You may see a difference depending on if the TPMS is temperature compensated.

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