My TPMS sensor came on and i had to reinflate one of my tires. The question is, since i have aftermarket rims/tires I have no idea what the pressure should be at. What tire pressure should I be having with 225/35/20 tires?

 

The maximum PSI a tire can take, is actually located on the tire itself. Just go look at the outer wall of the tire, and somewhere should be engraved the max PSI.

 

lol, Sidewall tire pressure is ftl, you can fill them up to sidewall psi but I would not recommend it.fill em to 35 all around

 

LOL, never fill to the max PSI. ur PSI will go up when ur tire's get warm.

 

Maybe I should've added what yall two said. lol. I was just directing where the numbers are actually are for his knowledge. I keep mine below max as well. Around 35-38.

 

Good starting point, then adjust up and down for comfort/feel. A pound or two either way can make a difference.

 

35's what I run.

 

^ 225/35/20??? that's a skinny tire for such a large rim! must look like hula-hoops...

 

I'd say 32-35

You aren't much wider than stock, so the contact patch hasn't changed much. Just keep an eye for abnormal wear patterns and adjust. I'd go so far as to paint a line across the tread on my car and inspect for even wear. It's how i determine proper tire pressure as different brand tires have different stiffness in them.

 

^ 225/35/20??? that's a skinny tire for such a large rim! must look like hula-hoops... my rim is only 7.5 width

 

You set the tire pressure based on the car not the tires. You can always find the correct tire pressure on a sticker in the driver's side door jamb. I think it is 33psi all around for my 06 6mt Sedan. A couple extra psi will give you better response, better fuel economy, and is better for high speed and aggressive driving.

 

I always wondered about PSI going up when driving, but my sensors go off after I drive for awhile (1hr +) for no apperant reason...This leads me to believe my PSI actually go down, as the tire gets warmer...clues?

 

Yeah i know its located on the door jamb, but i said i have aftermarket wheels/tires...so the door jamb is now useless to me.

 

This is one of the most retarded comments ever posted on DRIVER! You should never run your tires at maximum pressure! (50 PSI) The downsides are the center of your tires would wear out within 5K miles if not sooner and you'd have a miserable/terrible ride. Inflate your tires to what Nissan recommended which is 35 PSI, it doesn't matter if you have 17" or 20" tires/wheels....
Gary

 

psi cant go down as tire gets warmer unless you have a leak... when you drive tire gets hot, air expands and psi goes up... if you have a leak, you'd know it 'cause it would eventually go flat (of course the psi can go up and down with a leak)...

so in your case it sounds like one of your sensors is bad - have dealer check...