boybike

My Dealer (for only a few $$$ more) will replace my moist, leaking compressed air with Nitrogen that he says will leak less, is dryer and therefore better for the wheels and tires?

Is this on the level or is he just trying to make more $$$

Thanks
Bruce

UkroAvant

Definitely better...also Nitro doesn't expand/contract with temp, causing more stable tire pressures

stanj

The whole expansion is quite possibly about as true as explosive decompression on planes, or placebos. There was a very good, scientific thread on this a couple of years ago on the S4 board, and basiclaly, pV=nRT. The difference that can be shown by actual laws of physics is within the margin of error.

Egil A64.2s - S6

Placebo - LOL

thrilla from manila

minimal advantage for a lot more money, kinda like that vortex air inteke thingy mah jig

gk1

"The consensus opinion on Eng-Tips Forums seems to be that the benefits of Nitrogen are largely academic -- tires are engineered to be filled with ambient air, wheels are designed to cope with the moisture that air carries, and the benefits of Nitrogen, in real world applications, though real, are not worth the cost."

and another good point

"Car tire have a recommended COLD inflation pressure which takes into account the increase in pressure as the tires warm up. If you use pure nitrogen the increase would be less and the result would be that the tires would be under inflated hot."

caf

Keep in mind air is already mostly (71%) nitrogen...

UkroAvant

Here I am having taken physics all the way through quantum mechanics, as well as o-chem, and I couldn't even be bothered to check whether what all the tire shops I have ever gone to told me was true. LOL

John J Szobocsan

While it is true that the normal composition of the earth's atmosphere is 78% nitrogen and 21% oxygen, there is also the presence of water. Water is the real culprit in affecting tire pressure and, consequently, tire performance. Sometimes, depending on the temperature, the water in the tire is solid, liquid, or vapor. The various phase changes of water affect the overall tire pressure.

Also very important is that nitrogen is inert, i.e., non-reactive; something that cannot be said about oxygen. The oxygen present in the atmosphere, and present in the tire, react with the rubber compounds and, over time, cause the degradation of the tire. Nitrogen helps prevent this as well as prevent tire failure during high tire temperatures.

High performance aircraft, as well as high performance vehicles, use nitrogen gas to inflate tires for these reasons.

Sometimes argon, another inert gas, is used to fill luxury car tires because of better "damping" properties, as well as being more inert than nitrogen.