went to check the air pressure in my tires

and all of 'em were around 37psi!!!

i have not drivin my car for at least a good 36 hours

i haven't checked my pressure for at least a good 2.5 months

haven't added any air with in those months either

question is how did my air pressure rise with out adding air?

 

Air in tires increase due to warm or hot ambient temperatures outside.

 

well i checked it this morning and its where i left it off yesterday

 

My tC does that. I always put 35psi in all tires, then reset the tire pressure indicator. I checked the pressure of one tire and it was past 40psi after a week of driving (the weather has been moderate to cool). One tire though I believe has a slow leak, it frequently goes below 20psi and throws up the tire pressure indicator. Everytime the indicator comes on and I check, that one is low but another tire has higher than normal pressure. So far I'm running the stock Yokohama's and hope to replace them with BFGoodrich g-Force Sport's later this month.

 

Could it be that you are putting air in from a high pressure air supply and when the pressure drops it cools the air in the tires that later warms up and increases the pressure even more? SO you are actually measuring the pressure in the tire when the air in the tire is really colder than outside temps and when they warm up they increase. Also Since the outside air has increased a bit recently - if you were pumping them up in 30 degree temps and now it is 60+ degrees that also will make them increase in pressure.

 

Thanks Jan.. I'll lessen how much pressure I put in when I fill up next time, probably 25psi and recheck their pressure later in the day. Good info.

 

i also kind of thought if the barometic pressure messes with out tire pressure idk

 

Barometric presure is only a inche out of 30 so it really doesn't matter that much. More temperature than anything thing else But I would not start at 25 cold. You are better off a little higher than lower at all - will save gas and when you have to corner hard it will handle the loads better.

 

When tires pressures are set during cold weather they will rise as the outside temps do. The same way pressures go down after summers over. Happens every year. My guess is that you had them set around 32 during cold weather. Right?
Besides 37 psi is about right for high mpgs. during the summer season anyways.