# Tire Pressure



## firebird (Feb 6, 2011)

what are you guys running? For the Front oem tires, 235 18 40, and Rear 285 35 18?

what's the best psi for fuel economy, and then what would be the preferable psi for the traction/time?


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## svede1212 (Nov 1, 2005)

I run 35# with 245/45/17 & 285/40/17 all around. The firmer you run them the less rolling resistance. You just don't want to run them so high they wear just in the center or blow up . When I ran street tires at the track I ran 40# in the front and 25# in the rear.


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## Poncho Dan (Jun 30, 2009)

51 front 46 rear. No, it doesn't wear out the center patch, at least not on mine. I run max in the front to combat the slight camber wear, but mainly to keep wear even from hard cornering. A little less in the rear because there isn't as much weight back there. Same thing for both cars.

For grip I'd go almost all the way down to 20.


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## ZEIKE524 (Dec 28, 2010)

Poncho Dan said:


> 51 front 46 rear. No, it doesn't wear out the center patch, at least not on mine. I run max in the front to combat the slight camber wear, but mainly to keep wear even from hard cornering. A little less in the rear because there isn't as much weight back there. Same thing for both cars.
> 
> For grip I'd go almost all the way down to 20.


I am supprised the middles don't wear on yours. Mine were at 42# when i bought the car and the center was wearing pretty noticably. But if it works for you more power to ya. Better gas milage. But i run mine usually around 34# and yeah 20# - 25# for grip.


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## 87GN06GTO07IRL (Aug 10, 2009)

I run 32 on the street. The 265/35/18's on all four grip like crazy through the turns at that pressure. At the track 40 front 25 rear. I can see how anything below 25 on a radial tire can be beneficial in anyway.


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## firebird (Feb 6, 2011)

for the fuel economy now that is getting colder, i run them at 35 in front and about 36.5 in the back


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## Rukee (Feb 8, 2007)

I run the max listed on the side of the tires, also I fill all my customers tires to the max listed on their tires.


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## HP11 (Apr 11, 2009)

I've always been curious: Let's say you have two vehicles, one that weighs 2700 lbs. and one that weighs 3500 lbs. but they both run the same size tire. Wouldn't they require different tire pressures based on their weight?


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## Rukee (Feb 8, 2007)

HP11 said:


> I've always been curious: Let's say you have two vehicles, one that weighs 2700 lbs. and one that weighs 3500 lbs. but they both run the same size tire. Wouldn't they require different tire pressures based on their weight?


There are many different views on this. Some say to only use the tire clad in the door jam, but unless you replace the tires with the exact same brand and part # it's not going to be right, IMO.
I feel by filling to the max pressure listed on the tire`s sidewall that the tire itself will last the longest, give the best gas millage, and be able to handle the weight of the car. Remember, it's not the curb weight you need to concern yourself with, but at what weight the tire is handling say in an extreme cornering and braking condition. This is just my opinion~ and in 21+ years of service, have never had a tire issue by running the pressure listed on each tire.


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## HP11 (Apr 11, 2009)

Fair enough. I have heard a few differing viewpoints on this from people that I would consider to be equally as credible.:confused


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## ZEIKE524 (Dec 28, 2010)

Agreed its a hit or miss subject. some tires at max pressure will wear in the center. i have experienced this firsthand. also some tires wear great at max pressure. then i worked at national tire and battery for several years and another deciding factor is the sidewal/size of tire. generally if u stay the same size tire as stock the numbers on the door are pretty much accurate. but like i said everyones has different opinions and different experiences so experiment with what suits your car/driving habits best. imo


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## 87GN06GTO07IRL (Aug 10, 2009)

Rukee said:


> I run the max listed on the side of the tires, also I fill all my customers tires to the max listed on their tires.


You fill performance tires to 50-51psi? On a tire with reinforced sidewalls that will cause the tread to balloon. I've had excessive center wear on my Saturn at 35 psi.


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## HP11 (Apr 11, 2009)

I have the OEM BFG G Force Sport (17") on my 05. I don't think I want to run them at the 44 psi stated on the sidewall.


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## Rukee (Feb 8, 2007)

87GN06GTO07IRL said:


> You fill performance tires to 50-51psi? On a tire with reinforced sidewalls that will cause the tread to balloon. I've had excessive center wear on my Saturn at 35 psi.


Sorry, I just haven't seen any abnormal wear by running whatever is listed on the tire. The only abnormal wear I see is when the tires are grossly under inflated.


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## firebird (Feb 6, 2011)

i have noticed my mpg sky rocketed since i inflated my tires for street use. amazing, how i was getting like 13.7 mpg and now it varries from 17 to 19mpg depending on the traffic congestion. 

i agree that under inflated tires wear out quicker. the over inflated will only give you harder feel of the road as being stiffer, and hard starts on gto will not be efficient as tires will spin, but mpg will increase during driving. other thing to keep in mind if you're running more psi, is summer and long trips, where psi can icrease due to heat by several psi's. so long trips, i would lower by at least 2psi.


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## firebird (Feb 6, 2011)

a lil biased reasearch on my behalf. got stuck in the rush hour 2 days in a row, and found out i was getting actually more like 15.7. which is still better than the 13.7 that clock used to read. but otherwise it is 17-19 with little traffic.


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