Guys,

Yesterday we got the remnants of Ike (high winds and rain). I took the car out with no problems.

Then last night the temperature dropped off (not sure how cold, possibly the 50's).

This morning I got in the car and the TPMS light was on {the indicator that looks like this ---> ( ! ) } and it stayed on to the car wash. I checked it there, and none looked low.

So I drove to my gas station and grabbed the pressure gauge and checked them all. They were about 25psi, so 7psi under acceptable. I pumped them all up to about 35psi and drove it to work without another problem.

Just curious if the cold weather could drop the pressures like that?

 

yes.......

 

Temperature changes do change tire pressures; in your case I suspect the tire pressues were just barely above the TPMS warning limit, say 27 psi. Changing the temperature from 70F to 50F is an absolute temperature change from like 530 to 510, or 4% so the tire pressure changed by 4% or down to 26 psi. setting off the alarm. Which explains again why tire pressures are set for cold tires, not ones warmed by road use.
It was supposed to give you the alarm. Shows the TPMS is working.

 

Thanks for the answers.... I thought the TPMS was set to go off below 32psi?

Experiencing NO problems since I upped the pressure.

 

thats why you all should run nitrogen. stop by your local costco.

doesnt inflate or deflate.

due to cold or hot.

 

Nitrogen volume varies with air at close to the same rate. It's moisture in air that causes pressure fluctuations. And air is over 3/4 nitrogen anyways. I wouldn't fill with nitrogen unless it was free and widely available.

 

free....and theres a crap load of costco everywhere heh.
you can always fill normal air.

idk....my pressure never increases and decreases.

i check it in the summer a lot and during the winter. i usually never fill my tires.

 

I fill with plain old air and it only drops about 2-3psi every few months. And I hate costco, too many damn cars everywhere

 

X2


mustkeektypingtopleasethefitfreakgods!

 

i must be somewhat right for cavie to agree. that know it all monster heh

 

telling you...get there like 9 am. you will be first in line...when they open at liek 9:30-945

BArely any cars...

 

just wanted to point out that you're in san diego, california? so the temperature there does not fluctuate that much between seasons like it would where some of these people are from.

 

ah yes...but beware i used to live in North carolina.

so i know how the weather fluctuates.

i drive to palms springs on a weekly bases. so going from 80-90 degrees to over 100-115 degrees is a big change imo.


but yes understand able. but really, if you have just pump air into your tires at a gas station. and say you take a long road trip.
so the road is HOT as hell, your tires heat up. doesnt air inflate when it gets hotter?and un even pressure causes premature wear on the tires. not instantly but over time i believe it can do it.

i dont know im just stating what i learned when i worked at the costco tire center for a day or two.

ive read somewhere that nitrogen is great.

i believe it works, but this is kinda like the discussion between oils. some think its not worth it. but i dont know, its free so why not right?

 

^touche sir

 

If someone gives me the option down the road I'll probably go for it. I've heard about it before and seen some advertisements at Wal-Mart of all places (not sure if they do it).

But I'm not having any problems now... so I'll just keep an eye on it!

 

damned Physics... always causing problems...

Boyle's law - Wikipedia, the free encyclopedia

 

Sweet!!!!!


wait a minute......
How did I become the "Know it all monster"? lol

 

IIRC, the rule of thumb is 1 pound for every 10*.
Yes, tires heat up from warm weather, hot roads, and internal friction. Set pressures to what is recommended, with correction for ambient temps.
Underinflated tires will get hotter than billy-be-damned due to friction when running fast, so don't underinflate to compensate. My bride's ride wants MORE air for fast running; sez so on the gas flap.
Moon

 

indeed this is the best thing to do with the weather changes iv been doing this for years now this tire guy i know told me about it and i laughed at him at first till i tryed it i thought he was joking.(but this was when i first started driving and dident know crap about cars the only thing i know was GT on playstation )

 

Little off topic here, but yesterday my friend got a nitrogen machine in his shop so i went for the swap (guinea pig FTW). I am now at 94-95% nitrogen all around. Now we wait to see if anything changes....or not.