Originally Posted by ExpresswayFord
Isn't the purpose of sensors to tell you when you're losing pressure, eliminating the need to check them?
I would agree with at every oil change, but monthly seems a little unnecessary to me.
No, that's not the purpose of the sensors. A 25% drop in pressure means your tires are getting excessive wear. Tires can lose up to 4lbs of pressure each month. Further, in northern climates, when it gets cold, it takes more air to reach 35 pounds. So, when it gets WARM again (i.e. Spring), you can find your tires HIGHER than your desired pressure, and you need to LET AIR OUT. The TPMS isn't going to tell you to do that.
I check all my tires and fluids MONTHLY. This month I found that I had to let 2 pounds of air OUT of each tire to hit 35 (first thing in morning, in a garage, tires not heated by sun).
Waiting for an oil change, or your TPMS system to warn you, is NOT good tire care practice.
From Ford's website:
The tire pressure monitoring system (TPMS) illuminates a low tire pressure warning light when one or more of your road tires are significantly under-inflated. However, TPMS is not a substitute for proper tire maintenance, and it is the driver’s responsibility to maintain correct tire pressure.
It is possible for your tires to be partially under-inflated even if they are not so severely under-inflated that they trigger the TPMS warning light