when I had my pantera I drove fast out on the hwy. mostly 135 mph going to San Fran. or driveing to Phoenix, Ariz. for hours 145 to 154 mph I always had Nitrogen as driving at fast speeds the tires dont expand and are safer.

 

Exactly Jay, that's why race cars have been on nitrogen filled tires since the early 60's. You do get a small pressure gain with nitrogen, but its very predictable, NASCAR guys use that predictability to adjust the tire pressures just like any other suspension variable. Dropping a half pound of pressure might not sound like a lot, but on the track you feel it, trust me.

 

Exactly. Paying for nitrogen is like paying for a transmission flush or putting on slotted & drilled rotors. It certainly won't hurt anything, but there really isn't any benefit to using it on a daily driver.

 

With regular air, you have water vapor. With N2, you don't.

N2 is a "larger" molecule and cannot easily permeate through the tire. Its not actually larger, it is just less reactive since it is mostly inert. O2, however, is not as inert and LOVES to take electrons from its surroundings. This is how oxidation happens and corrosion ensues. Your rubber in-walls can break down-though its not all that substantial over the typical duty cycle of a tire if maintained properly.

You can blab all you want about how air is 78 percent N2, and about how N2 in your tires is a waste. I believe that it is not a waste. I know enough about chemistry to back up my choice to use it. If its free, why not. I won't pay for it unless its insanely cheap.

 

Just a wee thought.......

I was told (by two completely different sources) that GM AND the tire manufacturers consider the tire pressure gain when specifying tire pressures for a certain vehicle. For example....a specification indicates 30 psi COLD. As you drive the tire heats, and depending on the type of driving, increases the air pressure to 31, 32 ,33 or 34 PSI. That is the recognized and optimal OPERATIONAL pressure for the vehicle. Therefore, when using nitrogen fill, it MIGHT be wise to add a COUPLE pounds over the recommended.

Your car, your tires, your choice.

 

You still get a pressure rise with nitrogen Snoopy, but its a more gradual and predictable rise than you get with straight air. I would be hesitant to add any additional pressure to your tires when running nitrogen as you might experience a larger pressure rise than you anticipate. As nacademus pointed out you have water vapor in straight air that isn't present in tires filled with nitrogen, no water vapor means more stable tire pressures and less risk of corrosion to the tire components like the steel belts in the carcass.

 

You may be correct,,,but I don't think so.

But the crux of the statement is really IF your nitrogen filled tires meet the manufactures spec. on air pressure (since again, the spec is based on HEATED pressure). My thought, based on the discussion with a Firestone racing tire engineer and a GM engineer, at the recent Indy.....I don't believe so (unless of course, the tire pressure is SLIGHTLY increased).

 

I don't really see why oxidation would be a problem, most of that is going to be on the outside of the tire, not the inside.

Also, steel belts are going to be unaffected because they are encased in rubber. If your belts are exposed, what kind of air is in your tires is the least of your problems.

 

Your rim is not protected. You can get a rim leak from the inside out.

P.S.-rubber oxidizes. I would never PAY for it.

 

I work at a racing suspension company & we use high pressure nitrogen in all our shocks (cars & motorcycles). Heat causes expansion which causes friction, which causes wear, etc. The shocks dont necessarily use the Nitrogen for cooling purposes (as some believe). More for maintaining pressure balance within the system.
No water vapor in the mix either.
On cars, look for the green valve stem cap. These are the universal color for a Nitrogen filled tire.