Best tire pressure
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Joined: Jun 2020
Posts: 52
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From: Upstate NY
Best tire pressure
Hello all,
Have 4 275/40ZR17/98/w tires on a recently acquired '90 C4 standard coupe. Tag calls for 35#. When I first checked tire pressures they were all at 20#. Can't imagine that is right and increased them to 35#. Since then have read 35 may not be the best but no figures as to what is best. Any help would be appreciated.
Sorry, wrong forum.
Have 4 275/40ZR17/98/w tires on a recently acquired '90 C4 standard coupe. Tag calls for 35#. When I first checked tire pressures they were all at 20#. Can't imagine that is right and increased them to 35#. Since then have read 35 may not be the best but no figures as to what is best. Any help would be appreciated.
Sorry, wrong forum.
Last edited by murph350; Jun 9, 2020 at 09:01 PM.
Melting Slicks
Joined: Nov 2005
Posts: 2,074
Likes: 309
It depends on what your desired endgame is. If you're looking for cornering traction, lower might be better. Fuel mileage and tire life? Probably higher like the 35 PSI. I don't mean to be vague, but the "best" tire pressure doesn't exist and experimentation is required to arrive at a satisfactory number, and that number might change depending upon the weather and the road surface and front and rear pressures will probably be different.
Just don't go too low or too high, otherwise you might experience a tire failure. 20 PSI is probably lower than I would go but 35 is probably a safe pressure.
Just don't go too low or too high, otherwise you might experience a tire failure. 20 PSI is probably lower than I would go but 35 is probably a safe pressure.
Le Mans Master
Joined: Aug 2000
Posts: 5,529
Likes: 1,943
From: Austin Texas
Hello all,
Have 4 275/40ZR17/98/w tires on a recently acquired '90 C4 standard coupe. Tag calls for 35#. When I first checked tire pressures they were all at 20#. Can't imagine that is right and increased them to 35#. Since then have read 35 may not be the best but no figures as to what is best. Any help would be appreciated.
Sorry, wrong forum.
Have 4 275/40ZR17/98/w tires on a recently acquired '90 C4 standard coupe. Tag calls for 35#. When I first checked tire pressures they were all at 20#. Can't imagine that is right and increased them to 35#. Since then have read 35 may not be the best but no figures as to what is best. Any help would be appreciated.
Sorry, wrong forum.
But, if you really want to know, then you need a probe tipped tire pyrometer (about $90). with this device you can determine
a) proper tire pressure (the center temperature is equal to the average of the outside and inside temperatures)
b) proper camber (the outside is between 10º and 20º F hotter than the inside)
c) proper toes (average front temperatures are equal to average rear temperatures.)
