TPMS and Below Zero Temps

This morning was our first with sub zero temps. (-5 in Stevens Point, WI) When I started the Ridgeline up, the Low Tire Pressure Indicator stayed on and all four tires indicated low pressure on the truck diagram. Didn't take the time to check the tire pressure, I doubt my fingers would have worked. Has anyone else experienced this?

I realize there is a relationship between pressure and temperature. I only had to drive several blocks. In that timeframe one of the tires indicated it was ok. I'm assuming that with a little more driving all four would have cycled off and, more importantly, there is nothing to be concerned about.

It may be nothing to worry about but it sounds like your cold tire pressure is below the recommended 32 psi. You should check and inflate them to the proper specs.

No problems here at -10

My guess is the same - that the tires were slightly under inflated and the cold was just enough to get the TPMS to trigger.

Be sure to use a good dial gauge when you check the tires.

-W

This morning was our first with sub zero temps. (-5 in Stevens Point, WI) When I started the Ridgeline up, the Low Tire Pressure Indicator stayed on and all four tires indicated low pressure on the truck diagram. Didn't take the time to check the tire pressure, I doubt my fingers would have worked. Has anyone else experienced this?

I realize there is a relationship between pressure and temperature. I only had to drive several blocks. In that timeframe one of the tires indicated it was ok. I'm assuming that with a little more driving all four would have cycled off and, more importantly, there is nothing to be concerned about.

It was -11 here this am, and no problems.

I'm just glad the temps today are in the double digits (not by much!)

-5 in Stevens Point, WI
Years ago I used to drink "Point" beer. Do they still brew it?

You should check and inflate them to the proper specs.
Agreed! Your pressure is low or it wouldn't have come on.

Tire pressure drops 1 pound for every 10 degrees of air temp.

Here, it was 95 all summer. As the average temp fell to 60 I had to add 3 pounds of air in all 4 tires in the Vette.

So that's the relation of tire pressure to air temp. Driving on low air pressure creates friction, and additional heat when your sidewall becomes part of the contact patch which warms the tire, increases the pressure and turns the light off.

Cold PSI should always be maintained. Point is, if the indicator tells you it's low, add air.

Years ago I used to drink "Point" beer. Do they still brew it?


They're going strong and still independent.

This morning the on board temperature display read 8 degrees and I noticed that the TPMS sensor for the right-front tire was illuminated. I pulled out my digital tire gauge and it read 26 psi. I filled it up to 32 psi at the base air pump and the sensor light went out. This was the first time I've seen the sensor work on its own.

I just had my tires rotated and checked at 32 psi yesterday. I may have to keep an eye on it since the right-front tire just happens to be the full-size spare I had the trunk. It just might be a slow leak :(

It was -26 C (-15 F) this am. No sign of low pressure warning. One of the local tire shops offers to fill all four tires with nitrogen for $20. They claim a 4% increase in mileage and no slow leaks. They also say nitrogen gas is unaffected by changes in temp.

Anyone used nitrogen who can comment on same??

Gary P

I just had my tires rotated and checked at 32 psi yesterday.
Is it possible that the tires weren't cool enough to obtain an accurate reading?

I guess it's possible. I don't know how long it takes for the tires to cool off, but I drove straight from work to home then to the dealership. That entire trip was probably 6 miles and the truck was at the dealership for an hour.

I'd give tires 6 hours to cool for an accurate reading. You can probably allow less time, but then you will know they are cold. I always check mine in the morning before I move it from the garage.

As for nitrogen - excellent if you want to spend the money. Nitrogen is more stable than air. So if you fill the tire with nitrogen the pressure won't fluctuate with the air temp.

So if you fill the tire with nitrogen the pressure won't fluctuate with the air temp.
It will, unless you defy physics, just not as much as air does. May not even be measurable with a normal tire gauge, but it will fluctuate.

It will, unless you defy physics, just not as much as air does. May not even be measurable with a normal tire gauge, but it will fluctuate.

Granted. But not at the rate of 1 pound per 10 degrees.

If you fill the tires with Notrogen, what happens if your tires get low on pressure? Can you just mix the regular gas station air with the Nitrogen? Just a thought. I believe the Space Shuttle uses Nitrogen in their tires and that would make sense with the temp extremes it has to deal with; however, NASA has a bit larger budget than I do.

It was -26 C (-15 F) this am. No sign of low pressure warning. One of the local tire shops offers to fill all four tires with nitrogen for $20. They claim a 4% increase in mileage and no slow leaks. They also say nitrogen gas is unaffected by changes in temp.
Anyone used nitrogen who can comment on same??
Gary P


I know it can help just a little bit and consider flushing the tires with nitrogen from time to time but then I think normal dry air is already 78% nitrogen anyway. For it to be most effective you'd have to unbead the tires from the wheel, flush all the dry air out, bead the tire and then refill with nitrogen. I really prefer not to remount the tires as I think it it weakens the cords everytime it's remounted. If they just remove your valve core you're still left with a considerable amount of dry air in the tire. Considering all that I just say forget it and go back to normal procedures of checking/filling with tire with normal air.

If you fill the tires with Notrogen, what happens if your tires get low on pressure? Can you just mix the regular gas station air with the Nitrogen? Just a thought. I believe the Space Shuttle uses Nitrogen in their tires and that would make sense with the temp extremes it has to deal with; however, NASA has a bit larger budget than I do.


You can top off with air. You will only need to if you have a leaker. However, once you add air you lose the benefit of the nitrogen. Which is why I wouldn't spring for the nitro since it's not readily available if you're on the road.

My back right tire indicator came on this morning. This is the same one that came on a couple of months ago after the truck had been sitting in the drive for several weeks. I guess this time the reason is the temperature being cold.

Would love to know though why it is always the same tire (location) that seems to have a problem. The tires have been rotated since the first incident and are fine. I am beginning to suspect a rim leak. Has anyone else had this problem?

I admit I don't like the TPMS at all to be honest - just one more electronic with limited value to have something go wrong on, from my viewpoint. I have never had a single problem with tire pressures on my previous 6 Hondas when I had no indicator.

While the issue here may not be the indicator per se, I think I have only had to fill up the tires on my other Honda ('96 Civic) once in its lifetime of almost 200k miles to date - and when checked, they are still as they should be. But, then I have had no rim leaks on that vehicle either.

I wonder if I would have been made paranoid about a 1 pound change if I had had an indicator to tell me what my pressures were at all times. The Civic runs great, the mileage can't be beat, the pressures are always within tolerance, and I am obliviously happy with that state!

I would like the indicator to ONLY tell me if the tires go suddenly low while I am travelling at full speed, or alternatively, allow me to turn it off once I have viewed it, or to set the level at which I want it displayed perhaps might work too. I think the setpoint is too high given it is coming on quite often for what seems to me to be 'non-emergency' reasons.

Chiasma,

The TPMS doesn't come on until you get down to 24 PSI. Definately NOT too high, IMO. Perhaps you have a nail or other leak in your right rear tire? That's the benefit of the TPMS...to alert you when your pressure is low, but before it's completely flat.

Also, pressure drops when the temperature drops (about 1 PSI per 10 degrees), so if you added air when it was 70 out and it's 0 now, then that's 7 PSI. Plus, the approx 1 PSI per month drop expected normally.

Thanks for the reply, Swampler. Then I suspect the TPMS is faulty because I did take the truck to check the pressure and it was 31 for that tire! The others were all at 33. It was a bit lower but nowhere near 24.

I have had a lot of small issues with the electronics - caused, I believe, by water, but, three dealerships have not been able to find the trouble and I can never replicate it for them. They found one leak on the right front but I have felt the water drip on my left ankle when driving, while the alarms all went haywire. Perhaps there is still water in there - and it is now freezing (about 20 degrees overnight) and affecting the sensor in some way (although this was definitely not the first night it has frozen here recently - just the first time lately that the pressure indicator has been on).

1. Air is approx. 78% nitrogen, N2, and 21% oxygen, O2. So even if you put atmospheric air in the tire, it's already 78% nitrogen.

2. At normal tire pressures N2, O2 and water vapor will all behave as ideal gases, and follow PV=nRT. Pressure will increase or decrease to the same extent as the temperature increases or decreases regardless of which gas is in the tire. Even at 300 psi, which is about 20 atmospheres, there is little deviation. The comments about N2 not changing in pressure as the temperature changes are incorrect.

3. The rate of effusion (or diffusion) of a gas through a porous membrane depends on the molar mass and to some degree on the molecular size. N2 and O2 are almost the same size and N2 is lighter than O2 (28 g/mol vs 32 g/mol) so if either gas were to effuse out of the tire, nitrogen would do it more quickly. Keep in mind that tires are designed not to be porous membranes.

4. N2 and O2 both have essentially the same specific heat capacity, about 1.0 J/gK, and thermal conductivity, about 0.00026 W/cmK. Water vapor has a specific heat capacity of about 2 J/gK. But remember, water vapor will constitute less than 1% of the air in the tire. So the idea that N2 has different heat handling properties is also without merit.

5. The ozone, O3, in the atmosphere, which is a ground level pollutant, will do a great deal more damage to your tires than the O2 inside the tire.

Aircraft tires use N2 for several reasons. They can't afford to have water vapor freeze in the tire (they experience huge temperature variations). Tire explosions upon landing are less likely with N2. They also have N2 handy for charging hydraulic accumulators.

I find no reason to believe that N2 is going to produce a better ride, better handling and certainly no better fuel mileage.

Weight savings? If you run the calculations you could estimate that the wieght of the air in a tire is about 100 grams. N2 would weigh slightly less but certainly not enough to make any difference.

The bottom line is that for general passenger car tires or truck tires there is nothing to be gained by using nitrogen rather than air. The guys selling nitrogen are the only ones benefiting.

The TPMS doesn't come on until you get down to 24 PSI. Definately NOT too high, IMO. Perhaps you have a nail or other leak in your right rear tire? That's the benefit of the TPMS...to alert you when your pressure is low, but before it's completely flat.

Well, I took the truck down to the local Honda dealer today to find out why the back right tire was low or what the real problem is. On my way I noticed that, while the general 'tire' indicator remained on, the back right tire indicator went on and off several times.

The other tires were showing 33 lbs pressure and the problem tire showed 29 lbs. Definitely not down to 24 lbs.

I was told the TPMS will come on when one tire is detected to be inflated to about 4 lbs less than the average of the rest of the tires - not at 24 lbs per se. I guess it might also definitely come on at 24 lbs if there is a sudden deflation and it doesn't have a chance to react in the above manner. Apparently the 'balance' thing is the tripper most of the time, according to the tech and manager I spoke with.

They inspected the tire for nails, etc. then pulled the whole wheel off and tested it in water with 60 lbs pressure to check for tire or rim leaks. They supposedly checked the whole TPMS to be sure it was not faulty (I am told some have been!) No problems there.

They filled the problem tire and said they couldn't really find a problem ... until just before I left when the service tech reached into the valve stem and discovered the one on that tire was really loose. So, we may have found the culprit, but, I will have to watch that tire carefully for the next while to see if it begins to deflate again.

Well, I took the truck down to the local Honda dealer today to find out why the back right tire was low or what the real problem is. On my way I noticed that, while the general 'tire' indicator remained on, the back right tire indicator went on and off several times.

The other tires were showing 33 lbs pressure and the problem tire showed 29 lbs. Definitely not down to 24 lbs.

I was told the TPMS will come on when one tire is detected to be inflated to about 4 lbs less than the average of the rest of the tires - not at 24 lbs per se. I guess it might also definitely come on at 24 lbs if there is a sudden deflation and it doesn't have a chance to react in the above manner. Apparently the 'balance' thing is the tripper most of the time, according to the tech and manager I spoke with.

They inspected the tire for nails, etc. then pulled the whole wheel off and tested it in water with 60 lbs pressure to check for tire or rim leaks. They supposedly checked the whole TPMS to be sure it was not faulty (I am told some have been!) No problems there.

They filled the problem tire and said they couldn't really find a problem ... until just before I left when the service tech reached into the valve stem and discovered the one on that tire was really loose. So, we may have found the culprit, but, I will have to watch that tire carefully for the next while to see if it begins to deflate again.Glad you found the problem (hopefully) and thanks for the additional information on the pressure. Mine came on at 24 (the other 3 tires were at or about 26), so I assumed it came on at 24. As for the water check...that should have shown a leak at the valve as well unless they left the valve cap on during the test.

It was -26 C (-15 F) this am. No sign of low pressure warning. One of the local tire shops offers to fill all four tires with nitrogen for $20. They claim a 4% increase in mileage and no slow leaks. They also say nitrogen gas is unaffected by changes in temp.

Anyone used nitrogen who can comment on same??

Gary P
I can attest to that, since i bought my tires from costco, i've switched to nitrogen. When i got my RL i ask Costco if they can switch my air to nitrogen since i'm a member, they said no prob. Don't really need to fill again for awhile.

They filled the problem tire and said they couldn't really find a problem ... until just before I left when the service tech reached into the valve stem and discovered the one on that tire was really loose. So, we may have found the culprit, but, I will have to watch that tire carefully for the next while to see if it begins to deflate again.


This makes your story an even bigger mystery. If they were testing your tire with 60 lbs of air in water, wouldn't they have discovered the valve stem issue during that process while actually filling the tire?

Based on this, it seems as though you still don't have straight information.

I agree with you that it could indeed still be a mystery. I will watch carefully for any signs of deflation on that tire. If it happens again, I will have the truck back to them very quickly, demanding that they change out the whole TPMS unit or the rim or both.

The dealership I took the car to, the only local one, has been on my 'never go there again' list as a result of a very, very unsatisfactory previous visit - but, I didn't want to drive far to get this checked out so I gave them another chance. They were doing their very best to try to win me back when I came in the tire problem the other day, but, I don't trust them to know their own business as they failed miserably before.

My front right and rear left indicator's were on this AM when I went to the gym. It was -4F here, so hoping that may be the cause. When it warms up (if it does) later today, I will check the indicators and tire pressure at that time. Glad I searched and found this thread, I knew the cold may have caused it, but was concerned seeing two indicators on....

1. Air is approx. 78% nitrogen, N2, and 21% oxygen, O2. So even if you put atmospheric air in the tire, it's already 78% nitrogen.

...

The bottom line is that for general passenger car tires or truck tires there is nothing to be gained by using nitrogen rather than air. The guys selling nitrogen are the only ones benefiting.

So, seems like no one wants to believe that air and nitrogen are essentially the same. Some of us know better and save our money, right csimo? :D