Proper Pressure For New Tires/wheels

[Fruti]

Hello all,

I have a '08 GMC Sierra 1500 Ext.Cab. and I just got new 22" wheels and tires for it, but I don't know the proper pressure I should inflate my tires. The placard on the truck says 35 psi for the stock ones which are ona a 17" rim but my new tires are way diferent:

 

I got the NITTO NT420S 305/45R22 118H tires, which read a max of 1320Kg (2910 lb.) at 50psi

 

I checked the pressure that the tire retailer left on them, but I checked when the tires where "hot" and read 50psi!!! thats the limit stated on the tire!!! And I don't know if thats OK... So What would be the propper pressure to inflate them??

 

Here's some additional info from the placard that might help:

GVWR 2903Kg (6400lb)

GAWR FRT 1633Kg (3600lb)

GAWR RR 1701Kg (3750lb)

 

I hope you guys can help me with this, beacuse I've been all over the web and found nothing on how to calculate the proper presure for them... the best approach I've got is some chalk test on the thread to se if it wears off evenly...

 

Thank you in advance for your help.

Fruti.

[desrtrat]

i would say fronts 38 psi cold, rears 36 psi cold. that should give a good starting point. see how it rides, and keep an eye on any on them. 50 psi is a little high for every day driving bit if you need to load the truck up hauling a heavy load, then go to 50 psi..

 

[Zembonez]

i would say fronts 38 psi cold, rears 36 psi cold. that should give a good starting point. see how it rides, and keep an eye on any on them. 50 psi is a little high for every day driving bit if you need to load the truck up hauling a heavy load, then go to 50 psi..

 

50 psi will make it ride like a tank and wear the center of your tires quicker if you are mostly running unloaded. I run about 37 psi in mine (lower and I get a darn TPMS error) and they seem to be doing just fine.

[TxTruckMan]

I would actually go with OEM pressure or a little lower. I have 305/40R22s on my yukon and use 35 in the front, 32 in the rear. I even out the psi in the back when I tow or carry a load. Have almost 40,000 miles with this configuration with even wear. Maybe slightly more wear in the middle, which indicates a little too much pressure. All the tire people I've talked to say they are designed to be filled with the same pressure as the OEM recommends, and it's worked perfectly for me.

[Rocco715]

anything below a 50 series tire I usually keep 40 psi in it.

[Bostonsfavson]

I have 275/55/20 Toyo Proxes S/T tires and I run them at 40 PSI. If I were you, I'd give them a try at 40 PSI for awhile and see how it feels. If you find the ride a bit harsh, try putting them at 35.

[Fruti]

Thanks for all of your advice guys!

 

I'll try the 40 psi and see how it feels and maybe go lower if I feel it to bouncy!

 

Gosh! With these wheels I feel like I sacrificed confort for looks, because with the original ones the ride felt way smother...

 

Also, a couple of things I didn't knew is that I had to do the "Tire Position Learning" for the TPM system, since the sensors ended in different positions, and then get the rear brakes calibrated for this bigger size of wheel! ...What I don't know is if the sensors (the originals from my old wheels) have to be calibrated for a new pressure range...?? anybody knows?

 

Later I'll post a pic of the truck to see how you guys like the new shoes!

 

See you around!

Fruti

[VMax2007]

What I don't know is if the sensors (the originals from my old wheels) have to be calibrated for a new pressure range...?? anybody knows?

 

 

Maybe, depends on the difference in PSI. The TPMS is programmed with a "nominal" pressure and the range is +/- 10 PSI. This re-cal must be done with a Tech2 scanner. My dealer did mine for $65. The program is stored in the RDL module (remote door lock module)...believe it or not.

[TxTruckMan]

Also, a couple of things I didn't knew is that I had to do the "Tire Position Learning" for the TPM system, since the sensors ended in different positions, and then get the rear brakes calibrated for this bigger size of wheel!

 

See you around!

Fruti

 

What do you mean by recalibrating your rear brakes?

[Fruti]

What do you mean by recalibrating your rear brakes?

 

 

Well, that is something that the guys from the tire shop told me I should do if I feel some vibration on the rear brakes (drums) when I brake; they say that "the dealer can calibrate the rear drums for a bigger size of wheel than the OEM to compensate the wheel size difference".. So, I don't know, don't take my word for it, maybe it's just b.s

 

I did felt that vibrations but it was due to some clips in the studs that have to be removed if you use an aftermarket wheel... So, I didn't had to do that calibration, my brakes feel fine now...