I know that nitrogen tire inflation is a bit gimmicky, given that a regular "joe" like me will never actually feel the difference in the change in tire pressure when inflated with regular air.

But a buddy of mine has got a loaner nitrogen tank and filling cart to use for a couple of days and I'm tempted to try some nitrogen in my tires ... just to see.

 

Racing teams use nitrogen because it doesn't expand under temperature like normal air does, so they can fill the tires to a certain pressure level and know it won't vary much under extreme driving conditions. For the average driver, it's not worth the trouble. I check my tire pressure once a month, drive slowly (so the tires don't get too hot) to the closest gas station (1 mile or so) and check the pressure.

If you decide to go with nitrogen, you'll need to continue with it to have the "benefits."

 

Hey Stream how much does your tire pressure change from month to month? I have a 530i and a 330i. I noticed that my 330i pressure changes a lot. this past sunday i adjusted my pressure in the front to 39 and back to 46 like it says on the door panel. 2 days later(tonight) i decided to check it again and i had to adjust them again. the fronts where down to 37.5 and the backs to 43.5. is this normal????

 

Keep in mind you want to always check your tire pressure when the tires are cold. I keep my tires (Dunlop 18" runflats) at 36 rear and 44 front, check them monthly, and they lose between 1 & 3 lbs each--more than I'm used to. With prior cars, I'd only check every 2 months, but with my 545i I check every month, given how much they lose.

 

Ya I check my tires about once every 2 weeks and they lose about 1 to 2 lbs only... not bad.

Convience of having a pump at home and a pressure guage... I dont trust the petro stations ones anyways.

 

Every 2 weeks, and 1 to 2 lbs only??!!

This is the first car in many years that I haven't been able to go at least 2 months without having to fill the tires, and I use a high quality gauge. To me losing 1 - 3 lbs every month seems like a lot.

 

Ya... thats bout it... well I should mention somtimes I go a month w/out the need to pump any air... But ya usually I'll lose like 1-3 lbs in a month...

2 months??? I think my tires will go flat by then! (* ie. 3-5 lbs *)

Are you guys serious? can go like 2 months w/out needing to add air?

I mean... its air it'll leak especially with the bumpy roads... So I dont find it that abnormal for a few lbs loss in a month.

 

Using Nitrogen is no a new novelty, Check out the Tire Center at your local Costco, they actually have been Nitrogen to fill tires for the past 5 years or so, and don't be suprised when they gice you a car back with a green valve stem cap, that let's them know that it was filled with N2.

As mentioned by other memebers, it's more stable with increased temps

 

I hate those green caps... dont touch my car!

 

A couple of points:

1. All gases expand and contract with changes in temperature. Anyone remember the equation PV = nRT? Or perhaps P1V1T2 = P2V2T1?

2. "Regular air" is over 70% nitrogen to start with, so when you air up your tires with air from the regular old air compressor, you are already getting mostly nitrogen.

The point? I suppose I don't have one.