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Message: both temperature and "amount of air" contribute
Changed By: Steve (Morro Bay)
Change Date: January 03, 2011 10:17AM
both temperature and "amount of air" contribute
Change Date: January 03, 2011 10:17AM
both temperature and "amount of air" contribute
Treating the stuff inside the tire as an ideal gas at constant volume (decent approximations) means that pressure is proportional to the product of temperature and the number of air particles (mostly molecular nitrogen, I think). If either the temperature or the number of particles is reduced, then pressure goes down. If you suppose that the volume isn't fixed, then the pressure is still proportional to the product of temperature and the number of particles in the air, but now also inversely proportional to the volume.
It seems to me that somehow air leaks out of tires faster when the tires aren't used. One way to check this would be to measure both the tire pressure and temperature just before parking the car for the winter. Then months later, raise the tire's temperature back to whatever it was when you first parked it and then measure the tire pressure. If the pressure is not the same as when you first parked the car, and if the volume of tire is the same as when you first parked it, then some of the tire's air has leaked out. The hard part would be to find out if more air leaked out then if you had driven the car. So really you would have to repeat the experiment keeping everything the same except that you now keep the car in use during the winter.
It seems to me that you would find out that a parked tire does lose air faster than a tire that is driven on occasion. That's just my feeling from personal experience though. I don't know if it is actually true. And if it is true, I don't know why.
It seems to me that somehow air leaks out of tires faster when the tires aren't used. One way to check this would be to measure both the tire pressure and temperature just before parking the car for the winter. Then months later, raise the tire's temperature back to whatever it was when you first parked it and then measure the tire pressure. If the pressure is not the same as when you first parked the car, and if the volume of tire is the same as when you first parked it, then some of the tire's air has leaked out. The hard part would be to find out if more air leaked out then if you had driven the car. So really you would have to repeat the experiment keeping everything the same except that you now keep the car in use during the winter.
It seems to me that you would find out that a parked tire does lose air faster than a tire that is driven on occasion. That's just my feeling from personal experience though. I don't know if it is actually true. And if it is true, I don't know why.
Changed By: Steve (Morro Bay)
Change Date: January 03, 2011 10:13AM
both temperature and "amount of air" contribute
Change Date: January 03, 2011 10:13AM
both temperature and "amount of air" contribute
Treating the stuff inside the tire as an ideal gas at constant volume (decent approximations) means that pressure is proportional to the product of temperature and the number of air particles (mostly molecular nitrogen, I think). If either the temperature or the number of particles is reduced, then pressure goes down. If you suppose that the volume isn't fixed, then the pressure is still proportional to the product of temperature and the number of particles in the air, but now also inversely proportional to the volume.
It seems to me that somehow more air leaks out of tires faster when the tires aren't used. One way to check this would be to measure both the tire pressure and temperature just before parking the car for the winter. Then months later, raise the tire's temperature back to whatever it was when you first parked it and then measure the tire pressure. If the pressure is not the same as when you first parked the car, and if the volume of tire is the same as when you first parked it, then some of the tire's air has leaked out. It seems to me that a parked tire does lose air faster than a tire that is driven on occasion. That's just my feeling from personal experience though. I don't know if it is actually true. And if it is true, I don't know why.
It seems to me that somehow more air leaks out of tires faster when the tires aren't used. One way to check this would be to measure both the tire pressure and temperature just before parking the car for the winter. Then months later, raise the tire's temperature back to whatever it was when you first parked it and then measure the tire pressure. If the pressure is not the same as when you first parked the car, and if the volume of tire is the same as when you first parked it, then some of the tire's air has leaked out. It seems to me that a parked tire does lose air faster than a tire that is driven on occasion. That's just my feeling from personal experience though. I don't know if it is actually true. And if it is true, I don't know why.
Changed By: Steve (Morro Bay)
Change Date: January 03, 2011 10:12AM
both temperature and "amount of air" contribute
Change Date: January 03, 2011 10:12AM
both temperature and "amount of air" contribute
Treating the stuff inside the tire as an ideal gas at constant volume (decent approximations) means that pressure is proportional to the product of temperature and the number of air particles (mostly molecular nitrogen, I think). If either the temperature or the number of particles is reduced, then pressure goes down. If you suppose that the volume isn't fixed, then the pressure is still proportional to the product of temperature and the number of particles in the air, but now also inversely proportional to the volume.
It seems to me that somehow more air is leaking s out faster when the tires aren't used. One way to check this would be to measure both the tire pressure and temperature just before parking the car for the winter. Then months later, raise the tire's temperature back to whatever it was when you first parked it and then measure the tire pressure. If the pressure is not the same as when you first parked the car, and if the volume of tire is the same as when you first parked it, then some of the tire's air has leaked out. It seems to me that a parked tire does lose air faster than a tire that is driven on occasion. That's just my feeling from personal experience though. I don't know if it is actually true. And if it is true, I don't know why.
It seems to me that somehow more air is leaking s out faster when the tires aren't used. One way to check this would be to measure both the tire pressure and temperature just before parking the car for the winter. Then months later, raise the tire's temperature back to whatever it was when you first parked it and then measure the tire pressure. If the pressure is not the same as when you first parked the car, and if the volume of tire is the same as when you first parked it, then some of the tire's air has leaked out. It seems to me that a parked tire does lose air faster than a tire that is driven on occasion. That's just my feeling from personal experience though. I don't know if it is actually true. And if it is true, I don't know why.
Original Message
Author: Steve (Morro Bay)Date: January 03, 2011 10:11AM
both temperature and "amount of air" contribute
Treating the stuff inside the tire as an ideal gas at constant volume (decent approximations) means that pressure is proportional to the product of temperature and the number of air particles (mostly molecular nitrogen, I think). If either the temperature or the number of particles is reduced, then pressure goes down. If you suppose that the volume isn't fixed, then the pressure is still proportional to the product of temperature and the number of particles in the air, but now also inversely proportional to the volume.
It seems to me that somehow more air is leaking out when the tires aren't used. One way to check this would be to measure both the tire pressure and temperature just before parking the car for the winter. Then months later, raise the tire's temperature back to whatever it was when you first parked it and then measure the tire pressure. If the pressure is not the same as when you first parked the car, and if the volume of tire is the same as when you first parked it, then some of the tire's air has leaked out. It seems to me that a parked tire does lose air faster than a tire that is driven on occasion. That's just my feeling from personal experience though. I don't know if it is actually true. And if it is true, I don't know why.
It seems to me that somehow more air is leaking out when the tires aren't used. One way to check this would be to measure both the tire pressure and temperature just before parking the car for the winter. Then months later, raise the tire's temperature back to whatever it was when you first parked it and then measure the tire pressure. If the pressure is not the same as when you first parked the car, and if the volume of tire is the same as when you first parked it, then some of the tire's air has leaked out. It seems to me that a parked tire does lose air faster than a tire that is driven on occasion. That's just my feeling from personal experience though. I don't know if it is actually true. And if it is true, I don't know why.