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'07 CTS V
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24 Posts
Discussion Starter #1
A friend of my from Australia swears that running 40-45 PSI of tire pressure benefits feel, handling, and mileage. The only downside is a more harsh ride.

What's the consensus here?
 

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2009 CTS-V
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2,018 Posts
30 cold, 35 rides better but with the heat in south my tires will quickly overheat. I running on RSA-non EMT's
 

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2005 Cadillac CTS-V
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17 Posts
Higher pressures invariably result in two things: harsher ride and better fuel economy. Go as high as you feel comfortable, but be sure to check the maximum inflation pressure on your sidewall first. I've seen extended highway driving in high temps push tire pressures to 10psi over cold pressure, and lots of curves can have a similar effect.

It's also worth noting that CTS-Vs equipped with tire pressure sensors will repeatedly sound an irritating alert any time your pressures exceed 40/41psi. I don't care how much it improves fuel economy; I can't deal with that for any length of time.

//Edward
 

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2005 Cadillac CTS-V
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162 Posts
Anyone here put nitrogen in their tires? There's a big thing here with getting people to do this. They say the pressure change is minimal over a 6 month period. It does cost $24.99 but supposedly they will recharge your tires for free.
 

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2005 Stealth Gray CTS-V, 2009 Black CTS-V
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3,570 Posts
Cold, I keep my tires in the low 30s. Not necessarily because I want to, but more like because the STUPID alarm that goes off if the tire pressure equals/exceeds 42 psi. The tech at my dealership said he could NOT adjust it like he can in the CTSs. Anyone know how to turn that off/adjust them?
 

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'05 LS6 V Stealth Grey; '14 Z71 SLT Sierra 1500 Stealth Grey
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2,821 Posts
I just discovered a bolt in my rear left tire. Damn it. High twenties = low 30s while driving. That beeping is damn annoying. Some one else asked about the nitrogen before.
 

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2005 CTS-V
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8,363 Posts
I run 34 front and 32 rear with F1 GS-D3 EMTs. The amount of temperature gain from cold to hot is not constant in terms of PSI and is less with higher cold temperatures. You can determine your maximum temperature without setting off the alarms for your particular tire by starting with higher cold temperature pressures and backing down 1 PSI at a time under hot conditions until you find the cold temp that works when hot.
 

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2005 CTS-V
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8,363 Posts
I always recommend the following the vehicle information placard recommendations.
I don't disagree as those recommendations apply to original equipment tires.

However, one of the issues faced by many CTS-V owners is that they have replaced their OEM runflat tires, which have relatively stiff sidewalls, with non-run flat tires, which tend to have softer sidewalls. Having done that, they try to run higher tire temperatures to reacheive the crisp turn-in that the run flat tires had. The problem is that even though many of the non-run flat tires are designed for the higher cold temperatures required to "stiffen the side walls" that higher temperature results in hot temps that exceed the 42 lb. limitation in the CTS-V warning system. Hence, the alarms.
 

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'07 CTS V
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24 Posts
Discussion Starter #13
Forum,

Thanks for all the feedback so far. Another follow-up - Does anyone know if tires sold in Australia have different pressure ratings than those in the US - or if they at least have different numbers stamped on them?

I guess the question is - is the `32 PSI thing an American specific pressure geared towards a certain plush ride?

What I've learned so far is that my run flats with 29 psi cold should be pumped up about 4 or 5 psi and then tested for ride/performance. With the temps around 100 lately I'll also keep an eye on how the PSI's rise as they warm up.

Gunga galunga
 

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2005 CTS-V
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8,363 Posts
Forum,

Thanks for all the feedback so far. Another follow-up - Does anyone know if tires sold in Australia have different pressure ratings than those in the US - or if they at least have different numbers stamped on them?

I guess the question is - is the `32 PSI thing an American specific pressure geared towards a certain plush ride?

What I've learned so far is that my run flats with 29 psi cold should be pumped up about 4 or 5 psi and then tested for ride/performance. With the temps around 100 lately I'll also keep an eye on how the PSI's rise as they warm up.

Gunga galunga
My recommended pressures (per the owner's manual) is 30 psi front & rear for normal use. For sustained high speeds (130 mph) it goes to 32 front and 34 rear. The maximum tire pressure cold for the OEM tires, which were the F1 Supercar EMTS was 41 pounds. I believe the 30 psi base recommendation WAS NOT focused on a soft ride, because the tread wore out in the middle first when I ran 30 psi, which the signature of an over inflated tire.

The max on my new F1 GS-D3 EMTs is 51 psi. I have not run them long enough to establish a tread wear pattern.

I do not know what the corresponding numbers would be in the owner's manual for the 2006 and 2007 Vs since the OEM tire for them is a RSA EMT.
 

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2005 CTS-V
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8,363 Posts
Question: does a higher inflation pressure affect damper ("shock absorber") life?
Good question, but I suspect the answer is complex. I suppose in theory it could because the amount force not "dampened" by the tire effects the suspension. It gets complex from there though (at least for me) because the suspension consists of a spring that actually absorbs much of the force at a rate (speed) controlled by the damper (shock absober) in both the action (compression) and the correspnding reaction (rebound). Even this is an oversimplication because other suspension components and even the "suspended vehicle" ultimately get some of the force. After all is said and done, the answer beats the heck out of me. Bring in the physicist.
 

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2005 CTS-V
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8,363 Posts
No TPS on my track wheels. Since I check them after every run, there's no need. When on the track, you KNOW when a tire goes down...
Oh, now I seem to remember. Isn't there some need to make sure your TPS street wheels are not within a certain distance of the track so your onboard computer won't pick them up?
 
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