Tire Pressure
04-22-2017, 08:01 AM
#12
Foghorn Leghorn
Join Date: Dec 2006
Location: I reside in a near constant state of amazment.
Posts: 2,923
HA! Jokes on you, clowns! I am too that stupid.
But, in my defense, I have never had the centers wear down because for whatever reason, it seems that no set of tires I have ever had ever held at that pressure long enough for that to happen. I guess it's because I usually only check the tire pressure every couple of months or so and more often than not, it happens when I start noticing the handling going to schit. I guess if you're as lax at keeping up on tire pressures as I am, it turns out to be a wash. Witness my shame.
I have been through dozens of cars and sets of tires and not once, not once have they been replaced because of uneven tire wear except when I had an old Firebird that had a tweaked subframe that chewed through tires like bubblegum.
But, in my defense, I have never had the centers wear down because for whatever reason, it seems that no set of tires I have ever had ever held at that pressure long enough for that to happen. I guess it's because I usually only check the tire pressure every couple of months or so and more often than not, it happens when I start noticing the handling going to schit. I guess if you're as lax at keeping up on tire pressures as I am, it turns out to be a wash. Witness my shame.
I have been through dozens of cars and sets of tires and not once, not once have they been replaced because of uneven tire wear except when I had an old Firebird that had a tweaked subframe that chewed through tires like bubblegum.
Last edited by fastbackford351; 04-22-2017 at 01:31 PM.
04-22-2017, 03:00 PM
#14
6th Gear Member
Join Date: Aug 2007
Location: Elk Grove, CA
Posts: 5,896
Not as big a deal as it's made out to be.
The theory is:
Tires are porous; they slowly leak gas, everyone knows it.
Boyle's Law (PV=nRT, or P=nkT) dictates that tire pressure changes in direct proportion to temperature.
Nitrogen molecules are larger than oxygen molecules, and therefore will leak through the tire at a slower rate.
Nitrogen holds a more stable pressure across temperature ranges than standard compressed air, which is good for maintaining an ideal temperature despite varying weather and operating conditions.
This should mean that a nitrogen tire fill is great, right?
However, we need to remember that the air we breathe is already 78% nitrogen and only 21% oxygen. We also need to remember that daily driven passenger vehicles do not see the same operating conditions as commercial or race vehicles.
Commercial trucks have a tremendous volume of air contained in each tire, and fuel efficiency is a major concern for these vehicles. Being able to maintain proper tire pressure across a wide range of temperatures (these trucks may be in the snowy Rockies one day, and driving through Death Valley the next) for longer periods of time is critical to keeping fuel economy up.
Race vehicles see dramatic changes in tire temperature due to friction, with temperatures of each tire often being different. Being able to narrow the range of pressure change with changes in tire temperature allows techs to keep the tires at ideal pressure to improve traction.
Our daily drivers and weekend cruisers don't generally see the same kinds of variations in weather and operating conditions that these other vehicles do. Does a nitrogen fill help? Sure, but not as much as regularly checking your tire pressure.
Personally, I prefer not to be burdened by the green cap. If my pressure is low, I want to be able to hook the tire up to my own air compressor and top it off rather than being forced to drive to the tire store to have them do it. But an older couple that never checks the tire pressure on their Caddy unless the TPMS light tells them to would probably benefit from a nitrogen fill.
The theory is:
Tires are porous; they slowly leak gas, everyone knows it.
Boyle's Law (PV=nRT, or P=nkT) dictates that tire pressure changes in direct proportion to temperature.
Nitrogen molecules are larger than oxygen molecules, and therefore will leak through the tire at a slower rate.
Nitrogen holds a more stable pressure across temperature ranges than standard compressed air, which is good for maintaining an ideal temperature despite varying weather and operating conditions.
This should mean that a nitrogen tire fill is great, right?
However, we need to remember that the air we breathe is already 78% nitrogen and only 21% oxygen. We also need to remember that daily driven passenger vehicles do not see the same operating conditions as commercial or race vehicles.
Commercial trucks have a tremendous volume of air contained in each tire, and fuel efficiency is a major concern for these vehicles. Being able to maintain proper tire pressure across a wide range of temperatures (these trucks may be in the snowy Rockies one day, and driving through Death Valley the next) for longer periods of time is critical to keeping fuel economy up.
Race vehicles see dramatic changes in tire temperature due to friction, with temperatures of each tire often being different. Being able to narrow the range of pressure change with changes in tire temperature allows techs to keep the tires at ideal pressure to improve traction.
Our daily drivers and weekend cruisers don't generally see the same kinds of variations in weather and operating conditions that these other vehicles do. Does a nitrogen fill help? Sure, but not as much as regularly checking your tire pressure.
Personally, I prefer not to be burdened by the green cap. If my pressure is low, I want to be able to hook the tire up to my own air compressor and top it off rather than being forced to drive to the tire store to have them do it. But an older couple that never checks the tire pressure on their Caddy unless the TPMS light tells them to would probably benefit from a nitrogen fill.
Last edited by Starfury; 04-22-2017 at 03:03 PM.