yet another reason to think about Nitrogen. My Tire pressure is exactly what it was when filled. 42/40. 10K miles now not a single pound difference than when set.
Ignoring the possibility of a leak, PSI is guaranteed to drop as air temperature drops. Warning Tech Alert - The relevant formula is P*V=N*R*T where T is absolute temperature (P is Pressure, V is Volume, N*R is the amount of air in the tire). So a 50 degree drop in temperature results in approximately a 10% (4 PSI) drop with dry air (or nitrogen - no difference). Moisture in your tires can cause a slightly higher drop in PSI. (sorry, I'm an engineering professor and can't help myself) JeffD
That means (1) whoever mounted the tires did a good job, and (2) the tire temperatures were the same at the two measurements. The nitrogen fill had nothing to do with it other than being a relatively dry and inert gas; air, argon, or sulfur hexafluoride would have worked just as well :_>
Man! Don't let the cat out of the bag with that one! If everyone finds out about it.....then they'll all want it...... Nothing to see here....keep moving....
They can clamor all they want, but it's an extremely efficient greenhouse gas so it will never be legal for tires.
This time of the year, I check my tire pressure every 1.5 weeks not longer than 2 weeks. Only a couple of my tires are dead on the spot where I want it to be...and I add just a little air on the rest. Keep it this way and your tires will last longer too. I am a little over 14K now and tires still look great.
My TPMS light came on last week. The cold weather and the fact that I haven't checked my tire pressure since August both played a role. I pumped them back up to 38/36 and all is good. I'm putting on winter tires in the next few weeks anyway. I'm gonna have to live with that pesky light all winter long.
Yea, my light is on all the time now. Doesn't bother me in the least. Just another little tiny light up there on the dash like the others.
