brettxw

I have the firehawk indy 500s on my car, I only see a maximum psi but not a recommended like the other tires had.. What do you guys recommend for tire pressure? Some days I see it at 29...some days I see it at 31...i was thinking 32 or 33 should be good but with this Vegas heat I'm not sure.

jdbaugh1

iTrader: (1)

There should be a label you can see with the driver's side door open that lists recommended tire pressure and this is on any vehicle. I think it is 32 psi but not sure.

hawkssoccer11

iTrader: (13)

yes its 32. always on the drivers side door or door jam. thats what the manufacturer recommends.

brettxw

That's what I wanted to do but someone who supposedly works at a tire store told me that you can't go by that, it's based on the tire? I'll go by the door then. Thanks for the reply.

hawkssoccer11

iTrader: (13)

it is based on the tire somewhat too. but that will give you the best idea as to where it should be. use some different pressure settings and see which one you like the most.

brettxw

The door sticker says 33.

ECaulk

iTrader: (6)

I find 35 responds better with yyz on most tires

jdbaugh1

iTrader: (1)

I pump my Bridgeston Potenza RE-71R tires up to 38 psi for autocross. I typically run about 30 psi on the street for ride comfort.

ProfDNS

35PSI is recommended for SS/NA (G5GT).

For best tread life, I find 35-37 works.
30-32 for ride comfort (especially with tread <=70%)

brettxw

I happened to read through the manual the other night and it said that if I change tires I need to have the system relearn the tire pressure location or something.. Do I need to do that since they are new?

exninja

iTrader: (1)

You have to do that when you either change wheel locations or get new TPMS sensors. The car knows which sensor is at each corner, so if you move the wheel and don't relearn it will tell you the wrong location on the dash readout. I found that Discount forgets every time I get new tires so I have to make them do it when I get my car back. You can either use a handheld tool or there is a process detailed in the owner's manual.

brettxw

Oh, I understand now. I'm going to put some air in the now. Today the front showed at 28

brettxw

I'm gonna ask this question and I'll get flamed but it's okay. I want to make sure Im okay... It's 100+ degrees here in Vegas for four months.. This affects the psi in your tires correct? It will lower the psi.. Where as the colder it will show a higher number? If this is true, shouldnt I have it a little higher than normal? Again, Im sorry if this is stupid, flame on. Haha

jdbaugh1

iTrader: (1)

Are you talking about the effect of atmospheric pressure on your tires or tire temperature affecting tire pressure? If you measure the pressure of your tire while the tire is cold and then measure it when it is hotter it will be a higher pressure when it is hotter because of air wanting to expand. The inverse is also true. It's nothing to really worry about though. But say for instance when I autocross I drop air out of my tires after the first runs because my tires heat up and the pressure increases. Later when my tires cool back down the pressure drops a much as 7 psi from when they were hot.

brettxw

Oh, I had it backwards.. So the pressure in my tires could be even worse than I thought since they were 27 today while hot, they gotta be lower sitting in the garage. Blah. I appreciate that reply back. Thank you. I was gonna go put air in but a monsoon decided to come through Vegas and roads are flooded.

exninja

iTrader: (1)

Just go like 34 cold, 39 hot and you'll be fine. The most I've seen in a day is like 5 psi if that.

ProfDNS

Basic physics. Everything but water in certain types will expand when heated, contract with cold. (Science still doesn't understand why frozen water expands).

As long as you don't go stupid and fill your tires up to the max (or within 10% max), you allow for expansion and contraction in your tires without having to worry about it blowing - but you should check tire health fairly often, which includes leaks.

If I remember correctly, most if not all tires are vulcanized rubber to prevent shredding and blowing up under environmental distress.

Edit: Nylon threaded as well for extra strength

exninja

iTrader: (1)

Ice expands when freezing because of the crystalline structure