08-10-2011, 09:04 AM
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#1 (permalink)
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Corporate imperialist
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Nitrogen tires
I have seen claims that filling your tires with nitrogen will net you up to +20% MPG and some how the pressure doesn't change with temperature and it some how doesn't leak down like air (ha!). As if nitrogen is some how exempt from Boyle's law.
Back in 2006 I tested it and saw no improvements in fuel economy and charted pressure and temperature changes on par with air. Who would have thought since nitrogen only makes up 78% of air?
"Nitrogen filled tires" deserves the place of shame at the bottom of the wiki mod list page.
Last edited by oil pan 4; 04-19-2014 at 01:28 PM..
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08-10-2011, 09:44 AM
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#2 (permalink)
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Master EcoModder
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maybe use the search function.
there was just a thread on this topic.
geeez
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08-10-2011, 12:52 PM
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#3 (permalink)
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MPGuino Supporter
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Well, to be fair, N2 filled tires will generally experience less of a pressure fluctuation than air-filled tires, and that's because they use dry N2 for tire-filling. Air, on the other hand, contains water vapor which may condense out inside the tire, causing tire pressure to fall. If the pressure is bumped up, and then the vehicle is driven on those tires, the condensed water vapor will evaporate again due to tire heat buildup, and tire pressure will go up.
You could get the same performance of N2 if you took out all of the water vapor from the pressurized air. However, nobody in their right minds (?) would pay extra merely for "dry air" tire filling.
I'm certainly not going to rush out anytime soon to replace the air in my tires. They're good enough for now.
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08-10-2011, 01:20 PM
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#4 (permalink)
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Master EcoModder
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I agree, the claims are ridiculous. And the slight measurable differences are most certainly due to the water content, not the lack of CO2 and O2 in the tire fluid.
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08-10-2011, 02:57 PM
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#5 (permalink)
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Master EcoModder
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I call BS.
I have seen claims that filling your tires with nitrogen will net you up to +20% MPG and some how the pressure doesn't change with temperature and it some how doesn't leak down like air (ha!). As if nitrogen is some how exempt from Boyle's law.
Back in 2006 I tested it and saw no improvements in fuel economy and charted pressure and temperature changes on par with air. Who would have thought since nitrogen only makes up 78% of air?
I just ran 36,452 miles on Kuhmo 255/45/18 w/ nitro. Having just run 3 sets before on 02 for 120,000 miles.
The psi never fluctuated with the nitro. with the 02 there was always fluctuation.
and it was very easy to tell.........
The Q45 has psi sensor sytem that displays the exact psi on the screen.
show me in PRINT where some one claims the nitro doesn't 'leak' out? An idiot knows that a leak is a leak. nitro doesn't fluctuate.
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08-10-2011, 04:01 PM
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#6 (permalink)
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Master EcoModder
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Most of the modest benefits come from having no water (vapor) in the tyre as this causes most of the pressure variations.
The pressure will fluctuate with heat no matter what gas is used.
There's no way around physics.
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08-10-2011, 08:30 PM
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#7 (permalink)
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Corporate imperialist
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Normally its the snake oil sales men at the point of sale that will tell you about how nitrogen will defeat laws of nature.
You can search and find web sites claiming that nitrogen in your tires will cause pressure to bleed off 40% to 60% slower. The standard time frame they use is "between oil changes" so I take that as every 3 to 6 months. It should be checked every month.
I think figures like that and the snake oil sales men at point of sale give people false security.
This is what you need to know. There are something to the tune of 8,000 wrecks caused by tire failure each year and hundreds of deaths.
I tried to search to find the DOT figures but all I get is traffic lawyers and stuff about ford explorers rolling over with firestone tires.
People shouldn't be putting nitrogen in there tires and be under the impression they can forget about checking them.
Last edited by oil pan 4; 04-19-2014 at 01:30 PM..
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08-11-2011, 12:28 PM
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#8 (permalink)
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...beats walking...
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FWIW, our 2011 Cruze came from the dealership with green valve-stem caps bearing the letters "N2" on them...the dealership never mentioned whether they actually had put N2 gas into the tires or not.
...regardless, I just use regular "air" (78% N2, 21% O2) from the gas-station.
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08-11-2011, 03:11 PM
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#9 (permalink)
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Aero Deshi
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Quote:
Originally Posted by Old Tele man
I just use regular "air" (78% N2, 21% O2) from the gas-station.
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Even though the spring rate of regular air is 6.3 m/sec and Nitrogen is 6.25 m/sec???? And don't forget, the regular air has as much as 2% H20....This substance has been proven to be a gas, or, a solid, when it isn't being a liquid ....highly dependent on the ambient air temperature.
Yer taking some chances here. Good luck to you.
Last edited by ChazInMT; 08-11-2011 at 06:03 PM..
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08-11-2011, 04:46 PM
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#10 (permalink)
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...beats walking...
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..."regular" AIR has been used since the 1900's with great success, why change now?
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