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Found this on Jay Leno's Garage. Give the video time to load. If it doesn't work scroll down to GM Minute Segments. There is another video on nitrogen in your tires.
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Re: More noise from your Z06 and Nitrogen Tires
Nice tip. Thanks -
Re: More noise from your Z06 and Nitrogen Tires
The nitrogen works. I run a business with several service vehicles and have tested 1-2 of them with nitrogen. Better gas mileage, ride, etc.Comment
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Re: More noise from your Z06 and Nitrogen Tires
Jay Leno is a great comedian and Tonight Show host, but by his own admission he was a middling student, graduating from high school with about a C average.
He did not receive any higher education, and I would wager that he never took a basic physics or chemistry course any time in his lifetime.
The water content of air is in the gas (usually referred to as "vapor") state as long as the air temperature is above the dew point, and either non-saturated (less than 100 percent relative hunidity) air or nitrogen both behave as ideal gases and follow Boyle's Law, Pv = RT, which was discovered by the English scientist Charles Boyle over 200 years ago. So both non-saturated air and nitrogen will show the same pressure increase for a given increase in temperature in a fixed, closed volume despite the marketing hype and testimonials from those who develop anecdotal evidence from their own uncontrolled experiments that seemingly defies this science that has been accepted for over 200 years!
The problem occurs if the temperature of the tire's contained air falls below the dew point and water vapor condenses into liquid droplets. This will reduce tire pressure slightly relative to air that remains above the dew point.
Try to fill your tires on a relatively low humidity day. Pump the tank to full pressure and then let it cool to ambient temperature or about an hour. Set the regulator at about 50-60 psi. As the air flows through the regulator its temperature will drop (according to Boyle's law above), and if it is relatively humid, liquid water will condense out, but a good water trap will keep this moisture from reaching the tires, so the dew point of the air that flows into the tires should be lower than the ambient air.
Air's ability to retain water vapor increases with temperaturel; 80 degree air at 50 percent relative humidity has much greater water vapor concentration than 40 degree air at 50 percent relative humidity, so it's best to air your tires on a cool, dry day, and if the car never sits in ambient temoerature that drops below the dew point of the air contained in the tire (like sitting outside on a cold night), then liquid water will not condense out. If liquid water does condense out, it will evaporate and turn back into a gas once the contained air heats up to above the dew point, which a few miles of normal driving will usually do.
Back when service stations offered free air from their shop compressors, most had water traps, but I alway tested the air prior to applying the chuck to the tire. If any liquid water came out, I went elsewhere. Most of us probably have compressors and following the above recommended steps, including installing a water trap, should keep your tire air sufficiently dry to avoid condesation.
If you just have one of those electrically power tire fillers, avoid adding air in very damp weather.
The driest ambient air is always on the coldest winter day when ambient humidity is low.
DukeComment
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Re: Curious???? Z06 and Nitrogen Tires
Eric - Can't argue with success, but air is ~80% nitrogen and ~20% oxygen, so what's the reason (magic) with the improved performance? Maybe I should get rid of the NOS air in my 66 Corvette spare and put nitrogen in. PeteComment
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Re: More noise from your Z06 and Nitrogen Tires
Duke - Great info. Your other option is to drive to New Mexico, Nevada, Utah or Arizona and fill your tires up there. Have fun. PeteComment
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Re: More noise from your Z06 and Nitrogen Tires
We've been having a very dry and rather chilly late fall and early winter here in So Cal. The dew point has been as low as zero F, and has spent a lot of time below 35F, which is about as cold as it ever gets at my location a mile up from the beach. More typical dew points are above 40F.
Some may laugh, but I have actually "changed" the air in my tires when dew points are very low to ensure that the air they contain is as dry as possible.
It's cheaper than paying for dried industial air or dry nitrogen.
Yeah, I need to get a life.
Duke
P. S. My prediction is that we will be pounded by El Nino winter rains beginning later this month or next month. The US and world weather patterns are very similar to our last major El Nino event in 1998, and it could certainly effect you desert rats too.Comment
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Re: More noise from your Z06 and Nitrogen Tires
I've been reading information I now realize I never needed to know about, Jay Leno did make it through HS , I never did , started working at 15 and starting with my first car used AIR and thinking it worked for me so I'll stick with it.Comment
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Re: More noise from your Z06 and Nitrogen Tires
Roy - I agree AIR, filler up, it's a GAS!!!!!!!!!!!!!!!!!!!!!!!! PeteComment
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Questions about physics
Given that the vapor pressure of water is non linear, especially near the boiling point, wouldn't the pressure in a sealed vessel containing water vapor, like a tire, be non-linear?
One way to visualize this is to use a pressure cooker and vacuum pump to show the vapor pressure in a closed container. Put some water in the cooker and cool it as low as possible, freezing the water. Then seal the cooker and start evacuating it with the vacuum pump. You will never reach true zero psi vacuum because water will evaporate directly from the solid state to vapor, but you should evacuate almost all of the gasses, nitrogen, oxygen, argon, CO2, etc. so that the pressure is solely due to vapor pressure. Now heat up the pressure cooker and plot the pressure inside verses the temperature. It will be non linear. The link below is to a published table of water vapor pressures.
This is the performance benefit of using dry nitrogen, it reacts linearly while air, with water vapor included, reacts non-linearly, especially with tire temps near 200 degrees.
Vapor Pressure of WaterComment
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Re: Questions about physics
All homogeneous (single molecular component such as water) liquids have a vapor pressure that is unique function of temperature, but once all the liquid is evaporated, the vapor pressure curve of the liquid is irrelevant and the evaporated liquid behaves as an ideal gas.
As long as air in a tire does not cool to the dew point causing liquid water to condense out, that air, including the small portion that is water vapor, will behave as an ideal gas, and Boyle's Law is a linear.
The "boiling point" of a liquid is when the vapor pressure is equal to the ambient pressure. Vaporization occurs in the bulk liquid rather than just at the surface, which is why boiling water (or any other boiling liquid) generates bubbles. At 212F the vapor pressure of water is equal to atmospheric pressure, about 14.7 psi. At lower pressure water will boil at a lower temperature. That's why high altitude aircraft need to protect occupants with either a pressurized cabin or a pressure suit.
At about 60,000 feet your 98F blood, which is water based, will boil.
For the same reason, liquids cannot exist, steady state, in the vacuum of space. All liquids have a finite vapor pressure that is greater than the effective zero pressure of space.
DukeComment
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NASCAR race tires will pick up 7-10 PSI
in pressure even using nitrogen. when you watch a NASCAR race the next time after a pit stop look at the left front tire as it is almost flat when they leave the pits. with radial racing tires 1/2# of air pressure pickup changes the spring rate at that wheel about 10# that is why they can not start out with the correct pressure in the cold tiresComment
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Re: More noise from your Z06 and Nitrogen Tires
My lil' ole peapickin' head hurts from tryin' to read this post.Dick WhittingtonComment
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Re: Questions about physics
So we agree that the pressure relationship is non linear when liquid is present in a tire?
With liquid at equilibrium in a closed container, we would be at a saturated vapor pressure, but wouldn't there still be partial vapor pressure after all the liquid is evaporated and wouldn't that partial vapor still react per the non-linear vapor pressure table till the temperature/pressure point is in excess of the boiling point? In a pressurized tire, wouldn't this be well above 212 degrees F?Comment
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racing tire temp can get over the 212F mark
i will let you collage guys work out the theory but i know what happens at the track.Comment
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