What kind of air is behind your rubber

[ShocknAwe]

Had both, ended up buying a compressor and proper pressure sensor and check my tire pressure once a week. Don't like not being able to adjust my pressures.

[tommyb13662]

Originally Posted by greenc51

I also get BMW approved air by the can from the dealer

And if you huff it, it makes you a genuine formula one driver!

[YearOneOne]

Originally Posted by ShocknAwe

Had both, ended up buying a compressor and proper pressure sensor and check my tire pressure once a week. Don't like not being able to adjust my pressures.

why do you adjust them? you track your car?

[6MT_Addict]

Originally Posted by CincyOne

You do realize that our natural air is 78% nitrogen.

^^ this.

Also if you have your vehicles tires filled with air, and topped up with nitrogen, you're at maybe 80-85% nitrogen.

In order to truly fill a tire with nitrogen you would have to first purge the tire of air, completely. Next purge the line of air, then fill the tire. Realistically probably some sort of fill/purge/fill/purge process to slowly increase the percentage of nitrogen from 78-95ish, as I doubt achieving 100% is easily doable.

Nitrogen is useful in a race setting due to its resistance to expansion/contraction as temps change.

For daily drivers it's a scam. I learned the above from a close friend who started his own tire company, and refuses to sell nitrogen. He also owns/built/races two nascar style race cars, so I take his word for tire related info lol.

[YearOneOne]

As long as I can get it for free I'll stick with it lol

[fcman]

Originally Posted by ShocknAwe

Had both, ended up buying a compressor and proper pressure sensor and check my tire pressure once a week. Don't like not being able to adjust my pressures.

Same, I have a pump always in my trunk.

[ShocknAwe]

Originally Posted by YearOneOne

why do you adjust them? you track your car?

I do it for traction issues of any kind, track included. I'll also inflate them up ~2psi if I'm doing high speed highway driving, then let them back down when it get to my destination. Really helps with high speed stability. Lower pressures really help with off the line traction, though sometimes it's fun to go sliding about with high rear pressures.

[YearOneOne]

Oh ok gotcha. Very interesting!

[germ]

Originally Posted by Kev!n

The one thing I noticed in the 3-4 years we owned it is that it was at a stable PSI no matter the outside temperature.

As a physicist, I am afraid I have to convey you the bad news: this is simply not true. Gases obey what is called the "ideal gas equation," which basically states that the product of pressure and volume depends only on temperature. Assuming the volume of a tire doesn't change much with temperature (true in first order approximation), that is the reason why the pressure increases in hot weather.

While actual gases deviate a little from the ideal equation, I am willing to bet that the differences between oxygen and nitrogen are minuscule (too lazy to look up the correct coefficients right now). So my prediction is that in terms of pressure variation with temperature, both behave in very much the same way.

I don't know about nitrogen maintaining a more stable pressure over time. Because the molecular weights are very similar, here also I would venture a guess that there is not much difference, but I need to do some more research.

[JimD]

Another claim is that oxygen degrades the tire compound faster than nitrogen. But I think all the claims about nitrogen are either not true or way overblown in importance. It doesn't hurt anything to fill tires with closer to all nitrogen but it doesn't provide any benefit worth paying for.

I carry a Viair 70P compressor in the trunk. About $50 from Amazon. It comes in a little bag that I put a Accutire pressure gauge in and a plugging kit. That is my spare tire substitute. In several decades of driving experience I've never had a flat on my vehicles that having a compressor wouldn't have allowed me to drive home on. The plugging kit gives me a little more margin than I've needed so far and if all else fails I have AAA. But I don't have more than 78% nitrogen and won't pay to get it.

[twinboost_MD]

this is such a petty thread lol typical bmw convo.
If you wanna spend the extra money go ahead but it's pointless to justify the money spent for daily driving. just fill it with air and check regularly.. I think it's called like maintenance or something

[YearOneOne]

Originally Posted by twinboost_MD

this is such a petty thread lol typical bmw convo.
If you wanna spend the extra money go ahead but it's pointless to justify the money spent for daily driving. just fill it with air and check regularly.. I think it's called like maintenance or something

typical huh. i could care less whats in the damn tires as long as its something i was just curious