New Tires installed - air pressure question

[LDM]

I just got new tires installed: Nitto NT555 Extreme Performance ZR 255/45/17.

I took these pictures before checking tire pressure.

I drove it home after getting the new tires (18 miles), then let it sit for 1 hour before checking the air pressure.

The front tires had 41 PSI, rear tires had 40 PSI (seems high to me).

The max pressure on the tire says 44 PSI.

I lowered all four corners to 36 PSI.

Anyone have any recommendations? (Keep in mind they are wider and lower profile than stock).

The DOT codes for the tires are: 5210, 0111, 2111 (x2).

 

[Lownslowlsc]

I would think anything between 30-36 would be acceptable. Imo anything over 36 for a typical dd is too much.

Looks sharp btw..

 

[Wicked Ace]

If i know I'm going to be doing a lot of highway cruising I'll bump it up to 35 psi. Around town / normal trips 32 psi. I found much above 35 with the Michelin mxm4 is too much.

 

[Missing Linc']

Set them to 35psi cold, driving produces heat which will increase the pressure.

 

[fastmark1993]

70 psi with helium you'll gain 20 mpg

 

[Mechanicboy]

Set them to 35psi cold, driving produces heat which will increase the pressure.

Exactly. If you were driving on the hwy in the heat then the pressure will increase. 41psi hot is normal and when your tires are cold they might be low now. 44 psi max is the max cold pressure which is defined as the pressure first thing in the morning before the sun has risen and before the car has be driven.

The psi of a tire increase by approximately 1 psi per 10 degrees increase of external temperature. They also increase by approximately 4-6psi when driving in the hwy, sometimes more. Say the morning temperature is 60 and the afternoon temp is 90 and you've been driving on the hwy at 65 your tire pressure could easily increase by 9psi or more.

 

[LDM]

Thanks for the info everyone. I don't think they were too hot after only 18 miles (in town) and then sitting for 1 hour after that before checking the first time, but I checked again 1 hour later and they were still 35.5-36 psi. I will check the psi in the morning, to make sure they are cold when I check them again. I used to run 33-34 psi, which is why I was questioning 40-41 psi after I got home. I just put 110 miles on them tonight and they run great, smooth and quiet... and they did not hunt around on various interstates or highways that I took either. So far so good.

 

[Kumba]

I run my tires (245/40/18) at 34-35. It's the best compromise for me all things considered. If I lived somewhere with a bunch of landmines (potholes), I might run lower for more cushion, like 32.

Last I was at a track, around 40 seemed to be a good number. Definitely wasn't helping much on the DD part.