Tire Pressure : Hot or Cold?
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Tire Pressure : Hot or Cold?
There is a lot of talk about tire pressure in this forum, however most people forget to mention how they are getting their measurements. Were the pressures taken after driving on a 90 degree day, or after the car had been sitting for 24 hours in a garage?
What made me post this was my own personal findings. It's gotten pretty hot here now, 80-90 day to day. I hadn't set my pressure since I put these bad boys on in March. It was probably 50 degrees and the car hadn't moved at all. I set them at 35 front, 25 rear. I was able to do this because they were overfilled when they were mounted. The tires in question here are listed in my sig.
When I checked them yesterday after driving, I was shocked to find the fronts at 40-45psi and the rears at 35psi! That is much higher than 3 months ago. So, I let the fronts down to 35 and the rears to 25 which is where they should be for best traction and even wear. I'll have to check them before work some day (car is garaged) to see what the difference will be when cool.
So the question is, how and when are you checking your pressure? And when people recommend 25psi for the drag radials were they hot or cold? My thinking is it could be part of the problem for people with traction problems or uneven wear.
Also to add: I did notice the car was noticeably less responsive after I did this. Quick steering at speed was a little more "mushy" than it used to be, which I don't necessarily like.
Sorry for the long post. Maybe I should just fill them with nitrogen and be done with it.
What made me post this was my own personal findings. It's gotten pretty hot here now, 80-90 day to day. I hadn't set my pressure since I put these bad boys on in March. It was probably 50 degrees and the car hadn't moved at all. I set them at 35 front, 25 rear. I was able to do this because they were overfilled when they were mounted. The tires in question here are listed in my sig.
When I checked them yesterday after driving, I was shocked to find the fronts at 40-45psi and the rears at 35psi! That is much higher than 3 months ago. So, I let the fronts down to 35 and the rears to 25 which is where they should be for best traction and even wear. I'll have to check them before work some day (car is garaged) to see what the difference will be when cool.
So the question is, how and when are you checking your pressure? And when people recommend 25psi for the drag radials were they hot or cold? My thinking is it could be part of the problem for people with traction problems or uneven wear.
Also to add: I did notice the car was noticeably less responsive after I did this. Quick steering at speed was a little more "mushy" than it used to be, which I don't necessarily like.
Sorry for the long post. Maybe I should just fill them with nitrogen and be done with it.
Last edited by BlackHawk T/A; 06-07-2006 at 06:38 PM.
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I can tell ya that on my car (ws6) i keep the tire press 30 cold or 34 hot all around (275/40 17's). They tend to raise 5-7 deg when fully hot. 1 thing I've noticed, if the tires are inflated too high (ft or rr) it will dart/wander more on crappy roads. Hope that helped a bit.
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Originally Posted by KillerKlown
I can tell ya that on my car (ws6) i keep the tire press 30 cold or 34 hot all around (275/40 17's). They tend to raise 5-7 deg when fully hot. 1 thing I've noticed, if the tires are inflated too high (ft or rr) it will dart/wander more on crappy roads. Hope that helped a bit.
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Originally Posted by Rescue Ranger
I wouldnt've reduced your psi after driving it hot. Put the pressure where you want it to be when the tires are cold.
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Originally Posted by BlackHawk T/A
It would make sense to me that you would want to set them when warm, because that is the pressure you are going to have when you are driving the car. Why would you care about the air in your tires when it sits in the garage?
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Originally Posted by BlackHawk T/A
It would make sense to me that you would want to set them when warm, because that is the pressure you are going to have when you are driving the car. Why would you care about the air in your tires when it sits in the garage?
Because cold pressure is more "consistant" vrs hot . . .
And that is the way it has ALWAYS been recommended.
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Originally Posted by NHRAMAN
I try to keep mine around 32psi cold..all around....275/40/17 ....
The car sure seemed more responsive with 5psi more in the front though...
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your going to want to run 30psi in all your street tires.
running different pressure than what the inside of your drivers door calls for changes your whole suspension geometry. unless your an engineer and have calculated the effects for every +/- 3 psi your tires receives on each corner. then dont expect to get real world positive handling characteristics without sacrificing at LEAST that much on another aspect.
as handling will only be effected negatively by these changes.
running different pressure than what the inside of your drivers door calls for changes your whole suspension geometry. unless your an engineer and have calculated the effects for every +/- 3 psi your tires receives on each corner. then dont expect to get real world positive handling characteristics without sacrificing at LEAST that much on another aspect.
as handling will only be effected negatively by these changes.