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Discussion Starter #1
Does anyone know what the tire pressure of their 18" wheels and tires is because I just wanted to know..I know the pressure is monitered but on my Rav4 I had Tireax and 4 caps which when showing red they needed air..For good pressure they were in a green zone.....Thanks..This is for the Terrain....
 

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A good guide is always the tire/vehicle information sticker from the factory, usually in the driver's door-frame somewhere. Most tires need around low-30's (cold). 35 seems a tad high to me, but I'll do whatever the factory recommends.
 

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scottyyyc said:
A good guide is always the tire/vehicle information sticker from the factory, usually in the driver's door-frame somewhere. Most tires need around low-30's (cold). 35 seems a tad high to me, but I'll do whatever the factory recommends.
Should you though? Remember that when you replace the tires they will no longer be the GM OEM tires usually.

What you REALLY need to do is look at the maximum PSI on the TIRE not vehicle sticker. Then take about 15-20% off of that and run that PSI.

Ill trust the tire makers more than the car makers when it comes to tires.
 

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The recommended tire pressure on my last 4 cars was 35/35. Corvette, Tiberon, Caravan, Aztek
 

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Discussion Starter #7
OK 35 PSI..is that when they are cold>>Mine rise to about 37 all round when on road for awhile??
 

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Discussion Starter #9
OK when I am on the road..like to gym and back I see 35 all round..OK?? or should i put more in like 36 when Hot??
 

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What you REALLY need to do is look at the maximum PSI on the TIRE not vehicle sticker. Then take about 15-20% off of that and run that PSI.

Ill trust the tire makers more than the car makers when it comes to tires.


Wow, so the Car Manufacturer has spent time and money testing what tire pressure is best for the vehicle, and you are suggesting that one simply take 15-20% off of the tire's maximum PSI on the sidewall. SHAME ON YOU ! I hope you never drive one of the Ford Explorers that was subject to roll-over accidents caused by low pressure in Firestone tires. Remind me to never ride with you. (Sorry for being so harsh on you, but this sounds like a very unsafe recommendation !
 

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RIT333 said:
Wow, so the Car Manufacturer has spent time and money testing what tire pressure is best for the vehicle, and you are suggesting that one simply take 15-20% off of the tire's maximum PSI on the sidewall. SHAME ON YOU ! I hope you never drive one of the Ford Explorers that was subject to roll-over accidents caused by low pressure in Firestone tires. Remind me to never ride with you. (Sorry for being so harsh on you, but this sounds like a very unsafe recommendation !
Yes, for the VEHICLE. Not the tire. As of this time a Terrain can have 6 different types of tires. Does GM test every single tire and change the sticker on the vehicle for each vehicle? No, they dont. Ive seen it first hand in our Malibu. 16" wheels have the EXACT same tire PSI recommendations as the 18" wheels yet the tires were completely different on both vehicles.

Now, please explain it to me, how its unsafe to go by the TIRE manufacture rating that is on the sidewall? That is like listening to your podiatrist give you advice about your heart. ;)


Also, you do know why the Explorer had all those problems?? Ford recommended that the tires be at 28 PSI. Firestone stated that they needed to be a MINIMUM 34 PSI cold. People listened to Ford and when the tires blew Ford blamed Firestone for bad tires. No, the tires were run in conditions that they were recommended.
 

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See, 35 PSI seems "right".

On our Malibu its recommended for 32 PSI. The car feels pitiful with 32 PSI cold in the tires. After raising the PSI to 35 cold its a completely different vehicle. No, its not what is recommended by GM but it is what is recommended by Goodyear.

Also, NEVER did I say inflate the tire to maximum PSI. 15-20% off 44 PSI is what? Around 35-36. I guess GM is figuring it out. lol

Who knows more about tires? The tire manufacture or the car manufacture? Im going go with the tire guys.
 

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Discussion Starter #13
Yes 35PSI all around........That is when they are Cold??? Right??
 

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In this case, the 35 PSI recommended by the manufacturer (GM) "just so happens to" match the 80 to 85% "rule of thumb" that you have recommended. I say "just so happens to" because I HOPE that GM went through a rigorous test to decide what tire pressure to recommend based upon vehicle handling, design and economy. If they simply stick one generic sticker/recommendation on all of the 2010 Equinoxes, then I am disappointed with the amount of thought that went into the design of the vehicle. I can't speak about what they actually did, only about what I hope they did.

I know that at General Electric, when we design/recommend something on one of our Power Turbines, we do it based upon a rigorous analysis, not merely a rule of thumb. Maybe that is why GE did not face itself with bankruptcy while GM was on the brink.

Thank you for the "rule of thumb" - I will be sure to use it as a last resort when a vehicle that I own does NOT come with any tire pressure recommendation.

As a sidebar : it is Interesting that I just checked my Maxima, and the Max Tire Pressure on the sidewall says 44 PSI and the Nissan recommended pressure sticker on the door says 29 PSI. This winds up being 34% less than the max recommended pressure - outside of your rule of thumb.

Sorry for beating a dead horse... I guess we decided that 35 PSI on the Equinox seems to work, not matter how it is derived !
 

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nitti48 said:
Does anyone know what the tire pressure of their 18" wheels and tires is because I just wanted to know..I know the pressure is monitered but on my Rav4 I had Tireax and 4 caps which when showing red they needed air..For good pressure they were in a green zone.....Thanks..This is for the Terrain....
18" are set at 35psi. You cab see this on the drivers side door decal and owners manual. Hope this helps! Actually just checked mine today as I'm taking a trip from southbeach to Orlando.

Btw have any of you receieved a notice/brochure for nitro fill when you picked up your terrain. They gave me a year membership free and said not to use regular air. Nitro fill is a nitrogen and it holds longer etc!! Just curious. Thanks.
 

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bballr4567 said:
Should you though? Remember that when you replace the tires they will no longer be the GM OEM tires usually.

What you REALLY need to do is look at the maximum PSI on the TIRE not vehicle sticker. Then take about 15-20% off of that and run that PSI.

Ill trust the tire makers more than the car makers when it comes to tires.
You should always follow the recommendation of the manufacture of the vehicle. OEM tires and "non-OEM" will be the same pressure ratings
 

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grometsc said:
You should always follow the recommendation of the manufacture of the vehicle. OEM tires and "non-OEM" will be the same pressure ratings
Not true. Ive seen some "bad" tires that are rated for 38 PSI max. Generally, yes, they are rated for 44 PSI max.

I was shocked when I saw that on the tires, to be honest with you. However, when I heard the price of them ($38) I wasnt surprised then.
 

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SobeTerrain said:
18" are set at 35psi. You cab see this on the drivers side door decal and owners manual. Hope this helps! Actually just checked mine today as I'm taking a trip from southbeach to Orlando.

Btw have any of you receieved a notice/brochure for nitro fill when you picked up your terrain. They gave me a year membership free and said not to use regular air. Nitro fill is a nitrogen and it holds longer etc!! Just curious. Thanks.
Nitro has little effect in tires. You realize that dry air (meaning good compressor system used) is 78% nitrogen already. If your getting 90-100% nitrogen for free, then take it...I just do not find it worth paying for. It has slight benefits, but mainly those are seen in the commercial trucking side where airpressures are alot more important due to the loads the trucks are carrying, and the amount of miles the casing will run (proper inflation equals better wear). Its just not worth the money. Just do not use the mom/pop locations that have water blowing out of all the air lines when you look at the compressor system...avoid those places

My .02 after working in the tire industry for coming up on 10years for Bridgestone Bandag as a techncial support rep.

Not true. Ive seen some "bad" tires that are rated for 38 PSI max. Generally, yes, they are rated for 44 PSI max.

I was shocked when I saw that on the tires, to be honest with you. However, when I heard the price of them ($38) I wasnt surprised then.
http://www.tirerack.com/tires/tiretech/techpage.jsp?techid=8

Again MAX tire pressure has nothing to do with what you should run your vehicles tire pressure at. Its all about load carrying, and air is what carry's the load, not the tire. The tire is just a vessel to contain that air. Would I use a 38psi tire....No, I imagine it was a non-radial designed passenger tire, speed rated, but that is besides the point. If the manufacture calls for 35psi, and the max on the tire I just installed is 38psi I have the wrong type of tire for my application to begin with, but in order to carry the load the vehicle is capable of carrying I should run 35psi, other wise I could be running the tire under inflated. Tire rack has a good article and faq's for those that have tire questions.
 

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Yes, Tirerack and other tire places have articles about it.

Also, remember how long oil companies tried to shove 3k/3 month oil change intervals on us? ;)
 

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Fascinating discussion. So many people I meet do not understand that the Manufacturer of the auto determines the ideal pressure based on any tire meeting OE tires specs for load range,temp rating, and speed rating vs the auto.s spring rates, shock rate and advertised gross vehicle weight (curb weight plus max passengers/cargo) and safest ride quality desired by Manufact. Only then does it put a reccom air pressure sticker on the drivers door. But it is a COLD pressure, I.E.....driven less than 1 mile to a shop or first thing in morning, sitting in your driveway. Fluctuations can be a critical 4-7 psi , if car was just driven at 65MPH for 2 hours. Always check cold.

As stated elsewhere, Max PSI on tires sidewall is maximum burst rating for any applications (industrial?) ever used. NOT for your auto. 10 years as auto store Mgr taught me well . Sometimes the hard way 8)

MM
 
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