Tire PSI?

[scupking]

I know people say check the pressure when it’s cold. I checked them last week when it was close to 90. I filled them to 32psi. I checked them again this morning when it was in the 50s and my front left tire said 25psi and the others where around 28-30. So I filled them all up to 32 again. My question is should I fill them in the morning before the sun hits the tires?

 

[the98stang]

I know people say check the pressure when it’s cold. I checked them last week when it was close to 90. I filled them to 32psi. I checked them again this morning when it was in the 50s and my front left tire said 25psi and the others where around 28-30. So I filled them all up to 32 again. My question is should I fill them in the morning before the sun hits the tires?

It doesn't really matter when you fill them. Just keep checking them every once and a while.

 

[scupking]

It doesn't really matter when you fill them. Just keep checking them every once and a while.

I just didnt' think they would drop 7psi in a week. I guess a 40 degree change in temp could cause this.

 

[the98stang]

I just didnt' think they would drop 7psi in a week. I guess a 40 degree change in temp could cause this.

yea it's normal. your tires are fine

 

[chuck943]

The rule of thumb is your pressures will read 1 PSI less for every 10 degrees drop in tire temps, so if you were checking pressures cold then that would be about normal.

 

[GettinThere]

I know people say check the pressure when it’s cold.

I've always taken that to mean before the car is driven.

 

[tiptone]

I've always taken that to mean before the car is driven.

+1

I've always heard it in reference to the tire's temperature, they're 'hot' when they've been being driven.

FWIW, the factory sticker on the inside of the door of a Corvette I saw last week had the tire pressure listed and said add 4psi to the number if the tires weren't cold.

 

[2000fordstanggt]

i think you can drive up to a mile before they start to heat up and expand. but yes, youre supposed to check them when the car hasnt been driving in the last couple hours.

 

[jeffnoel]

+1

I've always heard it in reference to the tire's temperature, they're 'hot' when they've been being driven.

+1 it's tire temp not ambient air temp.