Search the web about nitrogen filled tires – especially in RVs - and you'll see a new order of religion. As far as the story you were told about that green RV, well, there are some seriously erroneous embellishments.

Yes, race cars use Nitrogen for its thermal expansion properties. Yes many tire stores have started to use it because 1) it is dry (unlike compressed air that can get condensate in it when they fail to check their filters) and 2) makes for a very fast tire fill (coming from a 2000psi nitrogen tank) and 3) it sounds cool thus making the buyer think they are getting something "better.".

Not sure how green that RV is given the energy it takes to produce 99% Nitrogen and compress it to 2000psi. Last I checked our Earth's lower atmosphere (the level we live in) consists of 78% Nitrogen, 21% Oxygen. So, the good old filling station air is already 78% Nitrogen. Your tires are exposed to the atmosphere so even with a 99% Nitrogen fill inside, the outside is exposed to the 21% Oxygen. No way around that. You are going to replace those RV tires at 7 odd years regardless of miles due to sidewall checking induced by UV in the sunlight and Ozone in the air.

I love these stories. They sound soo plausible... Besides, regarding the religion, if an RV driver can actually feel the difference in the thermal expansion of 99% Nitrogen over good old air at 78% Nitrogen, well, I’ll eat my tires...

But it does/did seem to be cool and fashionable to say I have Nitrogen in my tires, see the green valve caps? I'll bet today's reality/function based economy will change that perception in a hurry.

PS: Nitrogen typically comes in green painted tanks (hence the green valve caps), and should not be confused with Green environmentally.


-- Edited by RVDude at 16:54, 2009-01-27

It's a marketing scam to get some extra money out of consumers, for something that has been free ever since automobiles were invented. The reason bottled Nitrogen is used in airplanes is that it's totally dry and in race cars because the pressure int the tank is 2200# and the tires can be filled in a second or 2.
Save your money,

The use of Nitrogen would be prevelant in the trucking industry were it as beneficial as purported.  Large fleets of trucks spend many dollars to obtain the safest, longest life and least maintenance in tire management.

Having been close to these fleets for years, rest assured it is not one of their priorities.  Racing cars is quite a different application and may well be justified.

Charles

I know this is an old thread, but I couldn't help but respond. My new car came with nitrogen filled tires. That was in 2006. I have never had to put more in or make any adjustment whatsoever to my pressure. My understanding also, is that there is no condensation which can contribute to pressure variations. Seems to me it would work the same on an RV as it does on a car

Air is already 80 + % N2. 9% O2. Race cars use it to control the expansion of the water vapor H2O which is less than 1% of air. (There are other elements and compounds in air, like CO2, carbon dixoide.)