I notice that my on board psi readings are all over the place, each tire can be a different reading then they will all even out, then back to different numbers again??

i got the nitrogen in my tires and when my tires were heated up the psi was pretty steady with not much of an increase in psi. but I kept noticing those same different psi readings even with the nitrogen so i checked my tires and refilled with regular air and now i guess I have a mix of nitrogen and air and the hot psi's are goin up again to 37-38 psi with still consistent different readings!!!

2 things I learned,

1. do not listen to the onboard psi system, it lies

2. and nitrogen does help with your hot tire psi's staying steady, but do not mix regular air with the nitrogen, then your hot psi's will go back up!!

 

Lol, regular "air" is mostly nitrogen so your theory is flawed.

 

really, cuz chevy charged me $10 per wheel and it came out of a big fancy lookin machine!! and the psi's really did not increase that much with heat??

 

Air is 78% nitrogen.

The extra 22% they put in your tires helps a little but not a lot.

10 dollars is too much per tire.

 

So wait. You find it strange that your PSI increases as the tires build some heat in them?????

 

no, i know they do, howmuch? who knows, maybe 3-4 psi. i was just saying with the 100% nitrogen the psi didn't go up as much thats all

 

Nitrogen doesn't expand as much as "regular air" when it gets hot (not because it's nitrogen, but rather because there is much less water vapor in your tire), hence the consistent readings hot vs. cold. Also, the molecules are larger, which helps reduce pressure loss over time. Think of it not as filling your tires with nitrogen, but reducing the amount of oxygen and other crap you put in there.

Most tire places around me will give you lifetime nitrogen fills for a one-time fee of 20 bucks or so. (compare that to the Chevy dealership near me that charges 999.00 for that as a dealer add-on)