Tire Pressure?
Safety Car
Joined: Jul 2001
Posts: 4,661
Likes: 67
From: Ocean Springs MS
Originally Posted by Allzwell
Or you could go get on the train with some people switching to nitrogen inlation. It produces much less variation in pressure.
Team Owner
Joined: Mar 2001
Posts: 21,325
Likes: 3,841
From: small town in S.E Pa. PA
St. Jude Donor '03-'04
Its pretty simple: but this isn't brain surgery. But the fact is when your tires are cold and they are not turning, you get absolutely nothing in return for tuning your tire pressure.
Now when you are out on the road and your tires are turning, that is the time to be conscious of your tire pressure. Tire pressure is a very critical component to any high perform ace tuning. NASCAR, NH RA, SEMA, virtually all crew chiefs monitor road temperatures and adjust accordingly. one pound + or - can mean a few extra laps from the tires before a change, and just as important are handling and mpg, And the difference between winning and losing sometimes.
30 psi is a good number, but, it's a good number only when the tires are Hot and in the operating environment they will see as they turn that day. I am not suggesting that you adjust your tire pressure daily or by the hour, but use common sense. If your tires are cold and its 98 F in Georgia on a hot summer day, Black top road temps can get to be 140/150F. I have already done Lazar studies, just like the guys at NASCAR. Those Georgia or Florida or Texas asphalt roads can pump those 30 psi cold temps right up to 37/38 psi. They will not handle, like 30 psi. The sticker on the door was a product liability issue because many consumers were using the 44 psi max pressure on the side of the tire as the right tire pressure. WE see this here many times from newbies.
So if it's hot in the summer, 30 psi cold is too high. So you set them cold at 25/26, and in a mile or so your tires are tuned. Summer time is were most people lose some traction, wear out the center, and wind up with some squirrelly handling.
Spring and fall is much less demanding you only see 1 or 2 psi increase, so 28 cold is good...
This is of course all contingent on where you live. if your seeing 34, 35, or 36 psi readings in the summer, you are erasing your tire's tread, or getting less gas mileage, and seeing less handling quality.
The ideal footprint is just around 30 psi, which is NOT 35, 36, or 37 psi.
Many people have adopted this method and have seen similar tire wear as I have.. I had 43000 mile from my first set of EMT's with 3/32 left on the fronts and 2/32 still on the rears. Several guys have told me they were able to get 45K/48K out of their tires.
Also on the very flat Atlantic city expressway I routinely drive that 130 mile round trip, and consistently get 33 mpg.
I never let my tires get higher than 30/31 psi.
One psi can make a big difference in a 500 mile race.
IN your non racing driving experience 38 psi will cost you tire longevity, gas mileage, and handling.
I may change my tire pressure three or four times a year max.
Although I have posted this many times, it doesn't seems to make much sense to many. I only offer some insight and logic. Tire pressure is just as important as a good tune. Ask any crew chief next time your at a professional road event, Winston cup or Bush series race.
Sorry for the long post.
Now when you are out on the road and your tires are turning, that is the time to be conscious of your tire pressure. Tire pressure is a very critical component to any high perform ace tuning. NASCAR, NH RA, SEMA, virtually all crew chiefs monitor road temperatures and adjust accordingly. one pound + or - can mean a few extra laps from the tires before a change, and just as important are handling and mpg, And the difference between winning and losing sometimes.
30 psi is a good number, but, it's a good number only when the tires are Hot and in the operating environment they will see as they turn that day. I am not suggesting that you adjust your tire pressure daily or by the hour, but use common sense. If your tires are cold and its 98 F in Georgia on a hot summer day, Black top road temps can get to be 140/150F. I have already done Lazar studies, just like the guys at NASCAR. Those Georgia or Florida or Texas asphalt roads can pump those 30 psi cold temps right up to 37/38 psi. They will not handle, like 30 psi. The sticker on the door was a product liability issue because many consumers were using the 44 psi max pressure on the side of the tire as the right tire pressure. WE see this here many times from newbies.
So if it's hot in the summer, 30 psi cold is too high. So you set them cold at 25/26, and in a mile or so your tires are tuned. Summer time is were most people lose some traction, wear out the center, and wind up with some squirrelly handling.
Spring and fall is much less demanding you only see 1 or 2 psi increase, so 28 cold is good...
This is of course all contingent on where you live. if your seeing 34, 35, or 36 psi readings in the summer, you are erasing your tire's tread, or getting less gas mileage, and seeing less handling quality.
The ideal footprint is just around 30 psi, which is NOT 35, 36, or 37 psi.
Many people have adopted this method and have seen similar tire wear as I have.. I had 43000 mile from my first set of EMT's with 3/32 left on the fronts and 2/32 still on the rears. Several guys have told me they were able to get 45K/48K out of their tires.
Also on the very flat Atlantic city expressway I routinely drive that 130 mile round trip, and consistently get 33 mpg.
I never let my tires get higher than 30/31 psi.
One psi can make a big difference in a 500 mile race.
IN your non racing driving experience 38 psi will cost you tire longevity, gas mileage, and handling.
I may change my tire pressure three or four times a year max.
Although I have posted this many times, it doesn't seems to make much sense to many. I only offer some insight and logic. Tire pressure is just as important as a good tune. Ask any crew chief next time your at a professional road event, Winston cup or Bush series race.
Sorry for the long post.
Burning Brakes
Joined: Jan 2006
Posts: 818
Likes: 7
From: Senecaville Ohio
Rule for the air pressure obsessed:
Check tire pressures more often if subject to a wide range of outdoor temperatures, as tire pressures vary with temperature changes.
Tire pressures change by approximately 1 psi per 12 degree F of air temperature change. Keep this in mind when checking tire pressure inside a garage especially in the winter.
Example: If garage temperature = 68 degrees and the outside temperature = 32 degrees, then the cold tire inflation pressure should be increased by 3 psi which equals 1 psi for every 12 degree F for this outside temperature condition.
Tire pressure may increase 2 to 6 psi during operation. Do Not reduce this normal pressure build up or your tire pressure will be to low.
(And after all that, its allot easier to keep her at 30 psi all around!)
Laurie
Check tire pressures more often if subject to a wide range of outdoor temperatures, as tire pressures vary with temperature changes.
Tire pressures change by approximately 1 psi per 12 degree F of air temperature change. Keep this in mind when checking tire pressure inside a garage especially in the winter.
Example: If garage temperature = 68 degrees and the outside temperature = 32 degrees, then the cold tire inflation pressure should be increased by 3 psi which equals 1 psi for every 12 degree F for this outside temperature condition.
Tire pressure may increase 2 to 6 psi during operation. Do Not reduce this normal pressure build up or your tire pressure will be to low.
(And after all that, its allot easier to keep her at 30 psi all around!)
Laurie
Last edited by TomBoy; Feb 13, 2006 at 07:31 PM.
