I went to a tire shop today and saw this for the first time. I'm sure many of you know about this already. Instead of using compressed air to inflate your tires, they said nitrogen is better since it doesn't deflate as much. Temp is more stable. Tires last longer since it will not wear as fast. They were charging $4 a tire and free inflating for life.

I check the tire pressure often myself and don't mind it at all. Is this nitrogen thing just for them to make more money, or is it worth it?

 

yea it doesnt deflate as much overtime with nitrogen. I dunno about the tires lasting longer thing (doubt it), nitrogen is more stable than normal air, I dont think they run that much cooler since air is 80% nitro.

 

One main issue for the track guys is that the Nitrogen filled tire's pressure does not fluctuate as much during driving. When you go to the track and run hard, standard air will increase pressure ~10lb. So if you are running 30psi at track, you want to drop the psi down to 20psi to accomodate for the heat expansion. Nitrogen doesn't fluctuate as much, so no "tweaking" is really required.

Yes.. It's worth it if it makes you feel better...

 

It's a mixed bag. I had nitrogen in the tires of my M45, and they'd still gain as much as 4psi after a couple hours on the highway.

The reason is that they don't totally get the "regular" air our of the tires before filling with nitrogen. Most shops just take the valve cores out and let the tire deflate, then refill with nitrogen. That leaves a LOT of air in the tire, so you're not getting the full benefit of the nitrogen.

To do it right, they'd have to have be able to put a vaccuum on the tire to suck out all the air they could, then fill with nitrogen from the vaccuum. Most shops don't have the equipment to do that.

If I were you, I'd save my 16 bucks.
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Agreed. The real problem is humidity in the standard air, not the oxygen and minute quantity of rare gases. Removing the oxygen helps slow the breakdown of the inner liner material, but I've never seen a tire fail because the inner liner wouldn't hold air anymore, even 10 year old tires hold air (but you'd never want to run tires that old.)

Dry air will yield similar results to dry nitrogen. I know from road racing motorcycles that a dry nitrogen filled tire will only see a 1 psi increase at proper operating temperature compared to 4 psi with standard air.

AFA on a street car? Not worth $4 per tire.

 

costco will offer you nitrogen air for free provided you buy the tire from them...

 

Sorry for the thread drift but I disagree with this. Keep the pressure as recommended by your owner's manual or higher for the track as long as you're not getting too close to the max cold air pressure.

 

Agree with the other posts. Take the Nitrogen if it's free, but for $4/tire - save your money and just monitor your tire pressure on a regular basis. The TPMS will alert you if there's a real problem with pressure . . .

 

So.. you're telling me if you are running 35psi regularly, and then you get to track and warm it up (then the tires get to ~45psi), you would just run it as is!?!?

Doesn't make sense too me... Why would you want so much pressure in your tires out on track? You would lose so much traction with only a fraction of the contact patch actually on the pavement. I know many guys that run 25-30psi at track. Factroy specs are ?45psi? and then the heat expansion causes the tire to get to 55psi! no-no-no.....

 

Whenever possible, use nitrogen.

Been using for a while...my tires last longer...better adhesion to the road...track times more consistent...tires do not jump around on psi when hot.

When I take my RX to the track (see the photo at left), does not vary more than 1 psi from cold.

My tires are 44 max and I keep them at 39F/38R, more than recommendede...but way less rolling resistance.

 

yes. I actually run about 5 psi more on the track (usually 42 psi cold) than I do on the street. This is fine as my tires are rated at 51 psi max cold IIRC.

If we were still riding in bias-ply tires, then your worries about contact patch would be a much bigger concern. With todays belted radials, pressure doesn't affect the tread's contact patch as much as it used to.

25-30 is way too low IMO. With the increased heat, stress, deformation, etc., that track conditions bring, you don't want your sidewalls and tread squirming around any more than they have to.

As stated above, just make sure that you're safely under the max cold psi and you'll be fine. The manufacturer has listed it as cold psi for a reason and they've already taken into consideration the increased pressure from heat.

 

None of this discussion about track pressures means anything without tread temperature. The tread has an optimum operating temperature. If the tire is running too hot as measured with a contact probe or quality IR device, then raise the pressure. If the tire is not getting to the right temperature, then you lower the pressure. The absolute pressure numbers don't mean anything, the only thing that matters is tread temperature under racing conditions.

You DO take note of the track temperature, air temperature, and your starting pressures so you have a known starting point, but tire pressures should be adjusted to get the tire into it's normal operating range without regard for the absolute number on the pressure gauge.

You also need to take readings across the tire - the inside, middle, and outside portions of tread should be +/- 5 degrees F if your inflation and alignment are good for the driver and track conditions.

 

I agree lobuxracer, but I think these guys are talking about street tires. I don't think optimum temperature is a very effective parameter for using a street tire on a track. Actually, I think most street tires will get "greasy" at any air pressure in a 30 minute lapping session. For that same reason, I think Nitrogen is a total waste for street tires. Who really cares if a street tire gains 3 PSI while driving on the highway at 70 MPH?

 

The whole nitrogen thing is a huge ploy to extract $$$ from the ignorant, as regular compressed air is comprised of 78% nitrogen.

 

Sort of yes and sort of no. We used nitrogen in the landing gear struts of our WC-135B and in the tires particularly in winter because regular air (with its inherent water component) doesn't work well in aircraft at -30F in the air or -60F on the ground at Eielson AFB, AK. Lots of things don't like that kind of cold, so anything gas pressurised gets the dry nitrogen treatment.

For a street vehicle it's way overkill. That said, if I had a dry nitrogen cylinder, I'd be filling all my tires with it. I even have a backfill device I can use to pump them down first and backfill with N2. I doubt it will affect service life though. My driving has a lot more to do with that than anything.