TPMS

[GMTech48]

haha, well an even newer UPDATE!!

so i figured the one dumba:Yawn::Yawn: at the dealership didnt know what he was talking about, SO i called another one, one that has been in town longer, and he told me some new information!

PROBLEM SOLVED!! he said the TPMS would read up to about 45psi and well i went out in the cold rain and lowered them down to about 42psi each, and BAM! works like a charm. i might go back to the tire place and let them know, plus i might try and get them to fill back to 45psi, just to test the waters, i got the nitrogen filled and kinda wanna keep it that way and most gas stations dont have that, im sure they will be more than willing, especially with the new information i have :thumbsup:

well that was fun and learn something new everyday, or in this case alot :eek2:

the pressure range can be adjusted with the Tech2 so you CAN run the pressure you want.....your other problem will be the change in diameter will change your speedo calibration....that too can be reset but is more involved...dlr will need to call GM for a VCI # which costs $50 to the dlr.

 

[ozarkgolfer]

Quite simply...these LT tires need to run at 50psi in the front. 45psi is low. I have no idea why anyone would want to run lower pressures just because it makes the TPMS work or it saves them $150? How much are you going to save when the truck is in the ditch?

 

[07SuburbanLTZ]

Quite simply...these LT tires need to run at 50psi in the front. 45psi is low. I have no idea why anyone would want to run lower pressures just because it makes the TPMS work or it saves them $150? How much are you going to save when the truck is in the ditch?

i called BF Goodrich and gave them the specs to my tires and the lady said that a good psi for that specific tire is 40-45spi, said anything lower than 40psi is a no go.

He called the tires manufacture and they told him that he could run 40 to 45 PSI, just don't go below 40. So I would say it's safe to run 40+ PSI, no?

 

[uofmz71]

the pressure range can be adjusted with the Tech2 so you CAN run the pressure you want.....your other problem will be the change in diameter will change your speedo calibration....that too can be reset but is more involved...dlr will need to call GM for a VCI # which costs $50 to the dlr.

whats the Tech2? im not worried about the speedo calibration because its only off by about 3.2% so no big deal...

Quite simply...these LT tires need to run at 50psi in the front. 45psi is low. I have no idea why anyone would want to run lower pressures just because it makes the TPMS work or it saves them $150? How much are you going to save when the truck is in the ditch?

yeah the BF Goodrich people said that 50psi was still a little high, unless i had a heavy load, which i dont. They said 40-45psi was perfect BUT no less than 40psi! I mean this is coming from the people who make the tires! and i gave them specific details about the tire so that we would have no confusion, still 40-45psi but no less!

 

[ozarkgolfer]

We were talking Firestone and their site says 50 (for the front) - if another manufacturer quotes 40, 45 or whatever - go with that. It never hurts to run above the minimum psi stated - just don't run under - for your own sake! Check to make sure the rears presures are the same.

 

[bad63lac]

ozark,

The poster has a TAHOE. Not a Surburban. Also, why on earth did you run the numbers for a Suburban 2500??? Do you know the difference between 1500 and 2500?

A Suburban 2500 is the Suburban HD. Far cry from a normal Suburban let alone Tahoe.


Go back and run it for a Tahoe or a Sub 1500 and then come tell us what the magic number is.

Also, if you read your source which you are quoting, you will see they tell you to look in your manual or door sticker, not at the side of the tire.


The number on the door is based on what size wheels were equipped on your vehicle at the factory. The Firestone site is quoting the published numbers from GM. They are 30PSI for 17's and 32PSI for 20's for our trucks. GM quote's 35PSI for Escalade's with factory 22's.

For larger wheels you should bump up slightly higher in PSI due to the different sidewall heights. 35-42 would be ideal for 22, 24 or 26" wheels on our vehicles.

With that said, I run 40PSI in my 22" tires (bit better gas mileage).

 

[ozarkgolfer]

ozark,

The poster has a TAHOE. Not a Surburban. Also, why on earth did you run the numbers for a Suburban 2500??? Do you know the difference between 1500 and 2500?

A Suburban 2500 is the Suburban HD. Far cry from a normal Suburban let alone Tahoe.


Go back and run it for a Tahoe or a Sub 1500 and then come tell us what the magic number is.

Also, if you read your source which you are quoting, you will see they tell you to look in your manual or door sticker, not at the side of the tire.


The number on the door is based on what size wheels were equipped on your vehicle at the factory. The Firestone site is quoting the published numbers from GM. They are 30PSI for 17's and 32PSI for 20's for our trucks. GM quote's 35PSI for Escalade's with factory 22's.

For larger wheels you should bump up slightly higher in PSI due to the different sidewall heights. 35-42 would be ideal for 22, 24 or 26" wheels on our vehicles.

With that said, I run 40PSI in my 22" tires (bit better gas mileage).

The guy bought LT tires. LT tires are not standard equipment for a Tahoe so the information on the vehicle sticker is not correct for his setup. I used 2500 Suburban pressures from Firestone because a) they run the LT tire and 2) it was something I could link to, after a previous poster said he could not find any information on line.

 

[bad63lac]

Now that's some great rocket science if I've ever seen it. Please refrain from continuing to post bad information.


First, the info that Firestone is stating has NOTHING to do with the fact that they are "LT" tires. These aren't Firestone's numbers or research. Firestone is just republishing the vehicle manufacturer's recommendation because even as Firestone says on their website, the proper PSI is based on what the vehicle states not the tire. The reason for this is differences in vehicle weights and load/tow capacities.


The 50PSI front and 71PSI rear has nothing to do with Firestone or the fact that they are LT tires. It has everything to do with the fact that the Suburban HD (2500) has a curb weight that is 20% higher than a Tahoe or normal Suburban 1500 (Yukon and Escalade too for that matter) and is also presumed to be mainly used as a tow vehicle. Most HD owners don't have one to drive to the supermarket, they buy the HD to tow with. Based on the extra weight, the PSI is higher at 50PSI vs 30. Additionally the rear is bumped up even higher due to the presumed towing weight on a regular basis.


Again, PSI has to do with sidewall height and vehicle weight.


Per GM, for most 18" tires you need 30 PSI. For 20", 32PSI. For 22", 35PSI. If you are running 24 or 26", you need to go a little higher. There's a good reason that the TPMS sensor alerts you after 44PSI, it is too much air for the weight of our vehicles. (Tahoe/Yukon/Escalade/Suburban/Yukon XL/Escalade EXT & ESV)

Again, do not run 50PSI, regardless of "p", "lt" or other tire types unless you have a Suburban HD (2500).

 

[ozarkgolfer]

Just got back from looking at Michelin and Toyo information given to dealers - I had to go to a Tundra dealer, although the person in question runs an 07 Z71 Tahoe.

Anyhow...based on the LT tire sizes involved, if you run 30 psi all-round in your oem tire according to your doorjam info, you need to run a minimum of 40psi all around and recommended 45psi. The dealer also said - AS THEY SUGGEST - run slightly higher pressures in the interests of tire wear and fuel economy.

The dealer uses a chart/spreadsheet generated by the tire manufacturer that takes into account oem tire size, the new tire size fitted and load factors. The design of the tire...that it is an LT... has EVERYTHING to do with the tire pressures recommended.

 

[bad63lac]

opc1:


You're correct. Glad you verified and educated us on a 6300+ lb Suburban HD and what the "Tundra" dealer told you.


We're all wrong. GM is wrong.



:mog:

 

[ozarkgolfer]

opc1:


You're correct. Glad you verified and educated us on a 6300+ lb Suburban HD and what the "Tundra" dealer told you.


We're all wrong. GM is wrong.



:mog:

The numbers for a Suburban would be different - the numbers I quoted were for a Tahoe with 30psi oem tires changing to the LT tires quoted in previous post. Good luck and keep up the pressure.