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2003 DTS
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143 Posts
Discussion Starter · #1 ·
Yesterday I had an oil change at a Mobil 1 lube place. The "service guy", I won't call him a mechanic, started putting air in the tires. I said hold on as I have 30lbs of air in them which is what's on the door label. 2003 DTS. He says "oh don't go by that as the tires need 45lbs of air!" :bigroll: I said no just leave it alone. 45 will go to 50 here in Florida in no time. I have Michelin's on the car. So I come here for opinions. What pressure do you guys keep your tires at?
 

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'98 STS (RIP @ 206,xxx miles)
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4,854 Posts
My COLD tire pressure is 32 PSI front and 30 PSI rear with MY guage and MY compressor. Those numbers have worked well for my driving style and my rubber mileage for thirteen years.

Donut spare is 60 PSI.

PS; Avoid "lube places" if you possibly can.
 

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2002.5 F55 CORSA STS, 2014 Explorer XLT FWD
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73,392 Posts
The desired tire pressure is on the tire spec sticker on the driver's door.

All tires have a "maximum cold inflation pressure" statement molded into the sidewall: this is the MAXIMUM allowable cold inflation pressure to be used for extreme high speed driving - over 100 mph.

Normal passenger car pressures run from 30 to 35, with JimD's 32 psi being the optimum for ride quality, gas mileage, tire life, and handling: use a good dial type gauge and check/adjust pressures cold, never after driving, and DO NOT "bleed" hot tires: the pressure rise resulting from driving is part of the inflation equation.
 

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2003 DTS
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143 Posts
Discussion Starter · #7 ·
Thanks guys for your comments. I've been putting 30lbs all around since I had the car but this place insisted on 45lbs so "the tires won't wear out as fast". I wonder if I should notify Mobil about these clowns or would it matter? Also they used an oil filter called Service Champ. Anyone familiar with this filter? Thanks
 

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Super Moderator
2010 DTS
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88,120 Posts
As you said the sticker calls for 30 psi. That's where I run mine for a soft Cadillac ride. 45 psi is nuts, which is right where that grease monkey should be kicked. It would not hurt to call the owner of that place. 45 psi will wear the center of your tires pretty quickly and I doubt they'd pay to replace them.
 

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2013 ATS Premium 3.6, 1989 Allanté
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4,513 Posts
So everyone always says check the door stickers. Do tire manufacturer recommendations ever differ and if so, which do you follow?
 

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2003 DTS
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143 Posts
Discussion Starter · #11 ·
As you said the sticker calls for 30 psi. That's where I run mine for a soft Cadillac ride. 45 psi is nuts, which is right where that grease monkey should be kicked. It would not hurt to call the owner of that place. 45 psi will wear the center of your tires pretty quickly and I doubt they'd pay to replace them.
Yes I plan to. Thanks for confirming.
 

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04 Deville, 11 DTS Premium, 00 Deville (sold), 02 Deville (sold)
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2,691 Posts
So everyone always says check the door stickers. Do tire manufacturer recommendations ever differ and if so, which do you follow?
The door stickers reflect the numbers the GM engineers decided on when they considered comfort, handling, MPG's, tire wear, etc.. I run mine a little higher at 34 and sacrifice a little ride quality for improved tire wear. The max pressure numbers on the side of the tire are exactly that maximum tire pressure per the tire manufacturer... I really doubt that a tire manufacturer would ever go out on a limb and recommend different tire pressures than what GM recommended... remember the whole Ford Explorer / Firestone fiasco.
 

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2002.5 F55 CORSA STS, 2014 Explorer XLT FWD
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73,392 Posts
So everyone always says check the door stickers. Do tire manufacturer recommendations ever differ and if so, which do you follow?
The door sticker value is the car manufacturer's recommendation based on extensive testing of the OEM tire selected on that particular car.

A tire manufacturer will not make pressure recommendations because the same tire may be fitted on different size and weight cars of different makes.

The only tire pressure statements generally made by the tire manufacturers are the maximum cold inflation pressure (molded into the sidewall) and the recommendation to "use the recommended pressures in your owner's manual" - along with frequent, manual gauge pressure checks by the owner.

TPMS is for granny, not a car driver.
 

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03 STS
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2,527 Posts
we got new car and 6 months later a message came on telling me to check pressure. tire was 25lbs. month later it came on again. found nail pushed down between treads. hard to see. thats why i missed it at first. i like tpms.
 

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'98 STS (RIP @ 206,xxx miles)
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4,854 Posts
....TPMS is for granny, not a car driver.
TPMS is not only for granny. TPMS is a requirement per 49 CFR Part 571.

TPMS is fall out from the DOT / NHTSA investigation of the unfortunate Ford truck based SUV rollovers of years ago.

TPMS is not an option. Same as seatbelts and airbags among others.
 

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2013 ATS Premium 3.6, 1989 Allanté
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4,513 Posts
The door sticker value is the car manufacturer's recommendation based on extensive testing of the OEM tire selected on that particular car.

A tire manufacturer will not make pressure recommendations because the same tire may be fitted on different size and weight cars of different makes.

The only tire pressure statements generally made by the tire manufacturers are the maximum cold inflation pressure (molded into the sidewall) and the recommendation to "use the recommended pressures in your owner's manual" - along with frequent, manual gauge pressure checks by the owner.

TPMS is for granny, not a car driver.
I ask this ndxt part out of geniune curiosity. There are alot of things in life i still dont know :)

So disregarding any opinions on running tires and wheels other than what came stock on a vehicle, how do these recommendations apply to after market wheels and tires?

So for example, if a car with 15 inch wheels with a huge (comparatively) sidewall is recommended to run 32 psi will that recommendation still stand for 20 inch wheel with a much smaller sidewall?

I think the answer just popped into my head as i was typing this. The rating isnt a net amount of air into a tire. 30 psi in a stock tire requires alot more air than 30 psi in a smaller tire, since psi is a pressure measurement instead of a volumetric measurement. (Epiphany)
 

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Super Moderator
2010 DTS
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88,120 Posts
So disregarding any opinions on running tires and wheels other than what came stock on a vehicle, how do these recommendations apply to after market wheels and tires?
You're pretty much on your own in that case. Trail and error. The recommended tire pressure are only for that size tire.
 

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04 Cadillac Deville
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8 Posts
i also went to a oil change place & told them which oil i wanted even though they wanted me to use 10W-30 for a high mileage vehicle i told them no i wanted 5W-30 Synthetic because my car runs really good with that oil & after they stripped my oil plug & charged me for a new one, as i drove my deville home every time i hit a bump the car would move side ways to the left, come to find out they had put 39 psi on the left side tires, i would never go there again so i took out my digital tire gauge & brought the psi down to where i've had it for every car i've ever owned at 32 psi. it's a shame that most mechanics either don't know what they are doing or are just looking to charge u more money at the expense of messing up your car.
 

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2001 Seville STS, 1990 Seville (RIP), 1972 Sedan Deville
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Max, a heads up. Before you reply, check the post date on the last post. All 3 threads you've replied to so far are 1, 2, and 3 years old.
 

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00 Deville DTS, 120K Miles
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157 Posts
When I get to work on Monday, I will get the answer to converting my DTS(running 18's for winter) to a 255-35-20 tire size for the correct air pressure. A lot of it has to do with the load carrying capacity of the tire. For example if the tire is a standard load tire or extra load and if it's a 95 tire load vs a 95 tire load. I couldn't find an online tire inflation chart.

I run 36psi and I'm running 235-50-18 Dunlop winter sport M3s on my 00 DTS. That's my current winter set up.

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Damnit. If only I can read the previous post. Throw this crap away haha.
 
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