Filling car tires with Nitrogen?

grohl

Platinum Member
Jun 27, 2004
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" The local dealer charges $50 to fill tires normally."

LOL isn't air 75% nitrogen?

$50 is a rip off. Speaking of cars... Garage forum - Anandtech Moderator DrPizza
 

Cogman

Lifer
Sep 19, 2000
10,286
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Are these people really that stupid? "10% savings from fuel economy!" BS! the $50 they spend alone will negate any and all fuel savings. Seriously, how is filling your tires up with some magic gas supposed to all the sudden completly change gas mileage. If I where a local resident I would be furious I was paying the police to pay $50 for putting air in their tires.
 

walrus

Golden Member
Dec 18, 2000
1,544
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Air is 78% nitrogen already. Race cars use pure nitrogen because it doesn't have any water vapor in it that can change the tire pressure slightly at high temps. But it won't affect your mileage significantly
 

Cogman

Lifer
Sep 19, 2000
10,286
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maybe they should use hydrogen filled tires, its the lightest element out there, and when fuel cells and cold fusion take off they will be ready with their supply of hydrogen. Man this makes me mad :(
 

Dunbar

Platinum Member
Feb 19, 2001
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Ya, what a bunch of hogwash, if it truly increased fuel economy by 10% we'd all be "rollin on nitrogen". When I worked around business jets we'd fill them up with nitrogen. I think it is lower in moisture so it causes less corrosion and the gas is inert and won't support combustion (a big deal on airplanes.) Of course the tires were also inflated to 200psi which pretty much necessitated compressed tanks of gas, so in that case why not nitrogen?
 

db

Lifer
Dec 6, 1999
10,575
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Air migrates out of the tire faster than nitrogen. Many Costcos are now using nitrogen rather than air in their tire shops, at no charge.
 

Cogman

Lifer
Sep 19, 2000
10,286
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Originally posted by: db
Air migrates out of the tire faster than nitrogen. Many Costcos are now using nitrogen rather than air in their tire shops.

So basically you are saying they would have to refill their tires ones every 4 months instead of 3. I cant see it being a huge difference. As well, if this is truly the case then I would almost assume that the time before air refueling would gradually decrease as the natural nitrogen tends to leak less.
 

compuwiz1

Admin Emeritus Elite Member
Oct 9, 1999
27,112
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Well, what's worth doing, is worth doing for a profit. Welcome to America. :)
 

db

Lifer
Dec 6, 1999
10,575
292
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Originally posted by: Cogman
So basically you are saying they would have to refill their tires ones every 4 months instead of 3. I cant see it being a huge difference. As well, if this is truly the case then I would almost assume that the time before air refueling would gradually decrease as the natural nitrogen tends to leak less.

No. Because nitrogen leaks out through the tire much slower than air, a proper pressure is maintained longer. You can go 2 or 3 times longer without having to top off.
No big deal, it's not like someone is holding a gun to your head making you use nitrogen.
 

jagec

Lifer
Apr 30, 2004
24,442
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Originally posted by: Cogman
maybe they should use hydrogen filled tires, its the lightest element out there, and when fuel cells and cold fusion take off they will be ready with their supply of hydrogen. Man this makes me mad :(

Yeah, but hydrogen goes through most rubbers pretty easily...
 

Freejack2

Diamond Member
Dec 31, 2000
7,751
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What about helium? Then your tires won't explode and if you want to talk in a high pitched voice just suck some helium out of your tire. :p
 

Tyrant222

Senior member
Nov 25, 2000
802
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My dealer will fill it up with nitrogen for free. But they idiot techs will fill it up with different pressure in each tire. Just another gimmick. They have this thing called the 'butler' that looks like one of those car wash things but is suppose to 'wax' your car for $100 bucks. I just hide my laughter for later.
 

thomsbrain

Lifer
Dec 4, 2001
18,148
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Costco fills them with nitrogen for free. It leaks out slower (you need to add air only roughly 1/3 as often, which is significant), and it changes pressure less with temp changes. I wouldn't go out of my way for it, but it is definitely better than normal air, especially for folks who rarely or never check their tire pressure (this is where people will see economy increase).
 

boomerang

Lifer
Jun 19, 2000
18,883
641
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So if it leaks out 1/3 slower, when you do need to add to it, do you add air or nitrogen?

If you add air, you're just diluting the nitrogen and accelerating the loss of pressure.

If you want to add nitrogen, do you drive to, say, Costco to get it topped off? What if you have to drive a long way? Isn't that negating the supposed fuel savings of using nitrogen in the first place? How long does the average Joe drive on a low tire before noticing it?

This is a beautiful thing from a marketing standpoint. Keeps 'em coming back.

So many questions................
 

Pacfanweb

Lifer
Jan 2, 2000
13,158
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Good Lord, some of you are unbelievable.

First of all, more air leaks out past the tire bead and the rim than through the tire. There is about a 1% difference in how fast pure nitrogen (which the dealership machines do NOT dispense, BTW) and air diffuse through the tire.

Secondly, the reason race teams started using nitrogen in their tires in the first place is because they already had it on hand in compressed containers to run their air tools. While their MIGHT be some benefit on the track, there will be none on the street.

Thirdly, I do vendor work for this particular chain of dealerships, and even most of the people there know it's a bogus service. What you also get with a nitrogen fill-up is a roadside warranty...THAT'S what they're really selling.

One link explaining the BS

 

Pacfanweb

Lifer
Jan 2, 2000
13,158
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Do a google search for "nitrogen in tires". Scroll down the the Eng-Tips forums link. The link is busted, but view it using Google's cached page. There are numerous engineers there discussing this very topic, and there's lots of technical info in there showing that it's snake oil.