What is normal psi drop after X amount of miles?

[FlipTrac_511]

A few months ago I replaced my factory tires with Goodyear Fortera Silent Armors. They have served me well thus far but the psi seems to drop from 32/35 psi to 30/33psi (front/rear) about every 650 miles (or after two full tanks).



I've been checking the pressure on cold Saturday mornings where my Trac has sat overnight and, when necessary, filling them to 32/35 with a Craftsman electric air pump. I've learned that the gauge on this pump is whack but my current readings have been taken with two different handheld gauges.



I find it extremely odd that I'm getting readings that indicate a 2-psi drop all around after so many miles. I don't recall the orignal RT/S's doing this but then again, I don't recall checking their psi this religously. One Goodyear shop said it was normal but possible that my chrome rims are peeling causing leaks. Another shop was stumped as they'd never heard of the issue.



So whatcha folks think?

 

[Travis Munday]

Typical drop is around 1-2 psi every month. Certain wheel/tire combinations tend to leak more or less, depending on how well the beads of each mate.

 

[EddieS'04]

Also if some mornings are cooler now, that maybe it. Every 10 degree drop is 1psi drop..

 

[Richard L]

Flip-Trac,

Tiger is correct. 1-2 pounds drop per month is typical. Fast Eddie is also correct that air pressure drops as the temperature drops and since you should always check your tire pressures when the tires are cold, you will get a lower reading. Now is when you should inflate them to the pressure you desire. As you drive on the highway and tires warm up the pressure will increase by about 4 psi, but that's expected.



...Rich

 

[FlipTrac_511]

Thanks!