Why put nitrogen in your tires?

[SteveInMD]

What's up with tire dealers and garages offering to put nitrogen in your tires? Is there any actual benefit?

[merlin2375]

IIRC, nitrogen molecules are comparatively larger than compressed ambient air and therefore leaks out slower. All tires lose pressure through the tire walls or other small leaks so in theory nitrogen helps the tires stay at optimal pressure longer. IMHO, I wouldn't pay to have nitrogen but in but I am very much on top of my car maintenance and check my tire pressure regularly to maximize MPGs and ride handling/comfort. but I would take it if offered for free

[svey]

It will make a difference for the pressure sensor in your rim (if you have them), the nitrogen does not contain any moisture in it like regular compressed air does. The moisture is causing the sensor to rust thus giving false reading.

On GM with pressure sensor it is highly suggested to use nitrogen.

[zz4gta]

I was under the impression nascar used nitrogen, not for lack of rust, but b/c the nitrogen didn't expand as much as "air" when heated, therefore giving a more consistant pressure in the tires when they get up to temperature.

I could be way off.

[Freesail99]

I have a hand truck that I use to use every day. The tires were always going flat. I filled the tires with nitrogen a few years back, never had a flat again. Works great.

[SteveInMD]

The gas law PV=nRT says it doesn't matter what the type of gas is, the expansion will be the same. Now if you add moisture to the system, that can expand tremendously with temperature change. However, I don't think I'll hit those temps tooling around town.

Compressed nitrogen is usually much drier than air, so I can see the sensor corrosion issue.

If the oxygen leaks out faster than nitrogen, and I add air (which is about 80 nitrogen) when needed, I'll eventually have almost pure nitrogen in my tires!

[retclt]

I was with the wife dropping off her Camry for an inspection at the dealer last week. I saw a huge banner hanging that said “Nitrogen in you tires for only 39.95”. I looked at Cheri and said “there’s a sucker born every minute”. She looked back at me with the skunk eye and said “I had it done”. . . . . . . . . . . . Doh!!!

NASCAR may need that hair of an advantage but I don’t. It’s worth keeping that 40 bucks and adjusting my own once every few months. If Cheri needs a top off she has to go to the dealer for it. What a pain! I just drag the air hose out of the garage. The regular air I use is 78 percent nitrogen anyway.

[jrutledge33]

FWIW, I used to do tires for race teams.
nitrogen is a big help for competition. many teams now even use argon. it's all about the moisture content that comes from atmospheric air. tires will heat up to 225+ degrees and will go from 40psi cold to 55psi hot at places like Charlotte, even with nitrogen. use regular air and the growth gets enormous. causes issues with contact patch shape and spring rate of tire.

this is also why nitrogen is used in building shocks.

with that said, not much of an issue for daily driving. best bet is to drain down the compressor before filling the tires. most compressor tanks contain lots of water. $40 bucks?? that would pay for most of a large nitrogen tank. if you really think you need nitrogen in the tires, make sure they mount the tire with nitrogen or know how to properly evacuate the air the tire was mounted with.
hope that helps.

[cardiacpaul]

I fill mine with coke and pot... it throws the balance way off, but I find it fun. and profitable.

[LittleMissMagic]

Originally Posted by SteveInMD

The gas law PV=nRT says it doesn't matter what the type of gas is, the expansion will be the same. Now if you add moisture to the system, that can expand tremendously with temperature change. However, I don't think I'll hit those temps tooling around town.

Compressed nitrogen is usually much drier than air, so I can see the sensor corrosion issue.

If the oxygen leaks out faster than nitrogen, and I add air (which is about 80 nitrogen) when needed, I'll eventually have almost pure nitrogen in my tires!

I agree with Steve's post I only want to add that any compressed gas has a lower moisture content if it comes from a high pressure bottle. Most of the moisture is removed from the filling compressor.
This seems like a real gimmick for an everyday automobile.