I did a search and I know that stock tire pressure should be 35psi but I got some 19's on my car with 35 series tires with a max psi of 49 so I am not sure what I should be putting in them.

So running 10 psi under max sound right or???

Currently it is cold outside and not sure how much more I will drive the Z till after winter but want to make sure I don't do any dmg to my rims or tires.

 

i have the same size tires. for daily driving i just leave my 19's at 35 at the minimum. the most i'll go is 38.

 

35 Psi.

 

Max PSI is the maximum pressure that the tire can safely handle. 35psi is what Nissan recommends to run for the Z (regardless of tire size)

 

Consider getting a tire pyrometer and checking the temperatures across your tires. If the temperature in the center is significantly lower, the pressure is too low. Same for high temp/pressure too high.

 

Your question wasn't dumb, but this one probably is. Coming from someone who doesn't know JACK about cars, i got an alarming signal this morning from my car. It was 35 degrees when i came out this morning and my tire pressure was at 27 psi. Normally the tires run around 36 psi. If I read the manual right, am I supposed to adjust the tire pressure ANY TIME the weather fluctuates between cold and warm? I live in North Carolina and it can go from being 35 to being 80 in a matter of 12 hours. Can I get some guidance here? I'm a total dumbass when it comes to these things!

 

Tire pressure generally fluctuates +/- 1 PSI per every ~10 deg F. Given that formula, if you were to check/fill your tires in the morning when it is 30 deg out and set them to say 31/33 PSI. Then in the afternoon when/if the temp goes up to 80 deg your tire PSI will go up to about 36/38 PSI. Now this is all cold temp PSI, when you start driving that alone heats up the tires and causes the PSI to go up. Even direct sunlight will cause the PSI to be higher. Since the temp will more than likely not drop any more I'll have the PSI I started with as a baseline.

I've basically used this logic to balance the PSI to avoid over/under inflation when the temps fluctuate in the spring/fall and I think I’ve been successful. I check my tire PSI at lease once a month along with my other cars, having the TPS helps.

 

+1... Just FYI, I run 35psi all around. It's been working fine for 3 years.