TPMS & 1st cool day & Nitrogen
 

Two questions:
1) 1st cool day (61) since I got the Z. TPMS Alert is on.
a) What are the chances the cool air set this off?
b) Will it go off on it's own when the tires warm up?

2) Came from the Dealer w/ Nitrogen.
Refill/Top-off with N or just air?
(I know I'm asking for an opinion on this, but just wanted to know what you guys are running & what you think)

How long has it been since you purchased it from the dealer? It could have been coincidental that it lost some air during that time frame and the experienced temperature. When I had tires filled with nitrogen and I attempted to fill up with regular air, the gauge read low as nitrogen molecules are larger than that of compressed air. I'd take it to the dealer and have them refill (they should for free) or any place that offers nitrogen fill.

Try Costco, most have it and will for free

After air temp warmed up, all is OK. Gauged them anyway & OK

You need to test air pressure cold

Seconded.

On my '09 Touring, the TMPS light comes on when the pressure gets down to about 215kPa (found that out when I developed a small leak). If temperature changes are tripping TPMS, your pressure is too low.

You'll find all sorts of opinions about using N2. It does have some minor advantages (less leakage, less moisture) but it's not really a big deal. Ie, fill 'em up with whatever is handy.

Edit: And the TPMS on my car will auto-reset after a few miles at the correct pressure.

1a. Chances are high, get a guage and portable compressor.
1b. Maybe but just fill air 35-37psi cold.

2. You can't fill tire with full nitrogen with only one valve. You still have lots of air inside.

Follow 1a, 1b.

It will distinguish once tire warms up, however your pressures are WAY too low to drive if it is on. With low pro tires you really can't see the 5lb difference. I set my tires at 40 and let them cold soak over night. In the morning I set mine to 31.5 front and 30.5 rear. Getting pretty even tire wear on my car.

http://www.sears.com/craftsman-progr...p-02823020000P