Tire Pressure
Racer
Joined: Feb 2004
Posts: 321
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From: Murrells Inlet SC
Re: Tire Pressure (KenSny)
The radials of the 70's were of a stiffer sidewall and were made to be used on all the cars of the day. The Corvette was one of the lighter cars being made then, even though we think they are heavy now, so 20 lbs for the tire pressure gave good performance and helped the tires to "stick" when cornerning. Can you imagine putting 35 lbs in a 70's radial and taking a corner? You'd be slidding in circles.....
[Modified by MEAN72, 2:18 AM 4/10/2004]
[Modified by MEAN72, 2:22 AM 4/10/2004]
Pro
Joined: Jun 2001
Posts: 672
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From: Quebec
Re: Tire Pressure (wogs73)
What width are your tires? My 1980 came from factory with 255 60R15 and the recommended tire pressure is 26 Psi all around. If you run 225 70R15 in example, you would have to run something close to 28 or 30 Psi all around. I ran 30 Psi with my 255/45 R17 and they wear a little bit more in the center meaning overinflating.
It's a matter of contact patch to the ground versus weight of the vehicule versus air pressure. Bigger tire means bigger contact patch and when you apply 30 pounds per square inch to a bigger area, you can support more weight.
The white chalk or paint method describe above is the sure way if you don't run standard size tires.
Stephan
[Modified by American Boy, 12:42 PM 4/10/2004]
It's a matter of contact patch to the ground versus weight of the vehicule versus air pressure. Bigger tire means bigger contact patch and when you apply 30 pounds per square inch to a bigger area, you can support more weight.
The white chalk or paint method describe above is the sure way if you don't run standard size tires.
Stephan
[Modified by American Boy, 12:42 PM 4/10/2004]
Le Mans Master
Joined: Apr 2001
Posts: 5,000
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From: Minneapolis, Mn USA
Re: Tire Pressure (American Boy)
I run my 255/60/R15s right up at 34PSI with slightly warmed up tires by driving to the gas station. I prefer the better mileage with less rolling resistance and cant stand tires that look under inflated (bottom buldge). Never had a problem ever at this pressure and my tires dont show premature wear in the inside treads.
My ZR2 blazer 31x10.5/R15s BFG All Terrains pressure is at 50PSI, but I run those at 45 without problems too.
Most newer lower profile tires are up at 50PSI ballpark I beleive.
Brent...
My ZR2 blazer 31x10.5/R15s BFG All Terrains pressure is at 50PSI, but I run those at 45 without problems too.
Most newer lower profile tires are up at 50PSI ballpark I beleive.
Brent...
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Re: Tire Pressure
I've checked with the oldest old-timers I could find at work and none of them can recall wy tire pressures were set at 20 psi back in the 70s.
What I can tell you is that we wouldn't do it today. In general, 30-ish should be fine. 28-32, somewhere in that range should give you no problems at all.
Don't run at the max pressure on the sidewall.
What I can tell you is that we wouldn't do it today. In general, 30-ish should be fine. 28-32, somewhere in that range should give you no problems at all.
Don't run at the max pressure on the sidewall.
