bobsagator

iTrader: (13)

Well, I read thru the FAQ and found a little info, but still have a question. As per the FAQ:

I just moved from FL to TN and it is quite a bit colder up here. I never really paid attention to the cold air pressure talks because it really didn't apply in FL. But now I am ready to learn.

At this time I do not have the luxury of a tire pump (on my Christmas list, I've been a good boy) so I have to stop at the gas stations to check the pressure. Of course, by the time you get to a station, the tires are hot. So let's play this game. The outside air is colder so the presure decreases. But the tires are hot so doesn't the pressure increase (hot air expands)? So when checking the pressure when tires are hot in cold weather, should I just fill up to the 30-32 psi as normal? I of course would later check the pressure when cold and adjust if necessary but there aren't many free air places anymore and wasting 75cents each time gets old quick if it needs more air.

So in a nutshell: cold air outside with hot tires - how much pressure?

gelshmoff

iTrader: (1)

i think i follow your logic. but rather than trying to come up with a number, I would check your tire pressure before you get in the car in the morning. keep in mind which tires need more air, and fill at the station accordingly. just remember that your tire pressure will be different at the station than at your house, but the deficit in pressure should be similar.

then just check it the later or the next day to see if you got it in the ballpark.

bobsagator

iTrader: (13)

That's what I was thinking, I was just wondering if there was a rule of thumb or anything. Basically, I guess the main question is whether you add more or less air into hot tires to compensate for the hot vs cold reading. I would think that since the air expands when hot (increasing the pressure) that the gage pressure would be more than the cold tire reading. But how much more? If it is accepted that a 10 degree exterior temp changes pressure by 1 psi, then is there a general rate of change for tire temp?

yamahaSHO

iTrader: (2)

I've always checked and adjusted mine in the morning (about once a month) while still sitting in the garage. If the car sets outside, the sun will heat up the tires if there is direct light. Just keep it in an acceptable range as your pressures vary as you drive.

slystad810

Check the air pressure in all 4 tires before you leave the house and write them down. When you get to the air station, check all four again. Add the difference between the pressures to whatever you want the cold PSI to be.

Simple as that! Then check them once they are cold again just to make sure.

DDragon7

Well you coould just fill up extra when you are at the pump in the gas station and the next day you could adjust the pressure slowly.

gearbox

iTrader: (95)

yup, adjust them higher than you think, then next morning all you need to do is let the air out to the proper level

04civic07

iTrader: (13)

if it were me... after driving around normally for a good 10-20 minutes, i'd fill pressure up to about.... 30-34ish (assuming it's damn cold there) so i'd assume pressure will decrease to about 25-30 after it's been parked... but even if it's that lower, it'll warm up again and prussure will go back up... yay....idunno thats just me, ^but like gearbox said, thats a great idea.^