TPMS woes

[fdcg27]

Forty psi at the first hint of cold weather eliminates all of these spurious TPMS warnings.
I've learned to do this with our two TPMS cars and it works fine.
I've also learned with both that TPMS is great for alerting you to a slow leak.
The puncture on the OEM LR tire of the Forester was repairable.
Sadly, the one on the RF of the '12 Accord proved not to be.

 

[AKhan87]

Originally Posted By: yeti
get a new wife.find a woman that won't nag you -- in person, or by "next".good luck with that.
have a good day.

LOL this is something I would like to say to anyone who complains about their wives, I don't get it, why put yourself through the hassle? unless your stay at home and she makes all the money (in my opinion your not much of a man if you do this, unless god forbid your disable).

Marry a good looking intelligent "enough" women for you (so you don't consider their requests to be "nagging" but rather responsibility your more then happy to take care of)

 

[AKhan87]

Originally Posted By: Miller88
I was at a tire shop with a friend last February (I believe?) and some lady came back in and wanted to return her defective tires because they all dropped to 29 during a cold snap.

wow, now that is priceless.

 

[sciphi]

TPMS saved me from getting a flat during morning rush-hour traffic. I started the car and the dashboard started dinging and flashing the low tire's PSI. That tire looked normal at a glance, except for the nail sticking out of it that had been hiding in the shadows once it was off the car.

In winter, the tires get slightly over-filled to compensate for temperature fluctuations.

 

[geeman789]

Originally Posted By: brslds
Change them over to nitrogen too.


"Regular..." air is almost 80% nitrogen already... and "pure..." nitrogen (not that your getting that...) still expands and contracts, and leaks, albeit ever so slightly slower...

Your tire pressure will still change with temp and time...!

 

[gaijinnv]

Originally Posted By: geeman789
Originally Posted By: brslds
Change them over to nitrogen too.


"Regular..." air is almost 80% nitrogen already... and "pure..." nitrogen (not that your getting that...) still expands and contracts, and leaks, albeit ever so slightly slower...

Your tire pressure will still change with temp and time...!


You're right, air is 78% Nitrogen, but that's not why Nitrogen performs better in tires than air.

Virtually all air that is used to fill tires contains moisture - more or less depending on how the compressor is set up and how diligent the maintenance on it is. The time of year (ambient temp) and climate (humidity) can also affect the amount of moisture in air used to fill a tire.

Nitrogen, on the other hand, does not contain any moisture (OK, OK, way less - virtually none).

All gases expand and contract with changes in temperature. Most, including Nitrogen and Oxygen, both expand and contract about the same amount in accordance with the ideal gas law.

What does not expand and contract at the same rate is the moisture. Moisture (water vapor) expands about 7 times more than Nitrogen and Oxygen. It is the presence of moisture in the tire that causes exaggerated pressure differences when a tire heats up on the highway and cools down overnight in the winter.

Less moisture in a tire means less difference in pressure due to temperature.

The worst thing you can put in your tires is the air from a gas station - loaded with moisture.

So ... if you want the most consistent pressure in your tires over a wider range of operating temperatures, Nitrogen should be your gas of choice.

HTH

 

[Nebroch]

Originally Posted By: Kamele0N
VAG has better solution than TPMS valves...

They have "tweaked" ABS system to that degree...that ABS sensors are checking
revolutions of each tyre (ok that they are doing since 90's too)...


That passive ABS monitoring is common system, but I guess EUSSR regulation doesn't accept it anymore, so VAG has pressure sensors too.

I think mandatory TPMS is a very stupid idea, ABS monitoring doesn't cost you anything unlike these sensors with their batteries. It always works and there is nothing to program in it.

 

[Vikas]

Quote:
And if you have slightly flat tire...that tire is spinning slightly slower than other 3 tires and therfore ABS system asumes that it needs to be refiled...
Isn't it spinning FASTER? It's diameter has reduced, so to cover the same distance, it has to rotate more aka faster than other tires,

 

[gaijinnv]

Originally Posted By: Vikas
Quote:
And if you have slightly flat tire...that tire is spinning slightly slower than other 3 tires and therfore ABS system asumes that it needs to be refiled...
Isn't it spinning FASTER? It's diameter has reduced, so to cover the same distance, it has to rotate more aka faster than other tires,


You are correct. Underinflation = faster rotation.

HTH

 

[George Bynum]

Originally Posted By: gaijinnv
What does not expand and contract at the same rate is the moisture. Moisture (water vapor) expands about 7 times more than Nitrogen and Oxygen.


I'm not disagreeing, but can you give an authoritative citation for that?

Thanks, George

 

[CapriRacer]

Originally Posted By: George Bynum
Originally Posted By: gaijinnv
What does not expand and contract at the same rate is the moisture. Moisture (water vapor) expands about 7 times more than Nitrogen and Oxygen.


I'm not disagreeing, but can you give an authoritative citation for that?

Thanks, George


I think what he means is that water turning into steam (water vapor) expands 7 times the original volume.

The problem is that even if you have a larger amount of standing water in a tire, only a small amount changes from liquid to gas. If one is racing, that additional pressure buildup is a disadvantage, but in street cars, it not only is a smaller amount of buildup, but additional build up in street tires is an advantage.

Overall, I can not see any advantage to using nitrogen in street tires.