i can definitely feel that i am getting a very constant PSI thru out the day! early morning to sunny daytime.. i can tell by the ride that im not loosing any psi while the tyres are cold! anyway! ive tried it and i like it!

but my only problem is.. whats the correct PSI for 21inch cayenne for nitrogen fill up?? inside manual book is with air only...

with air.. i did 37/42
so is there a factory number for nitrogen??

 

Shouldn't it be the same?

 

Yup. Same pressure for nitro as for conventional air. You'll also like that a proper nitro fill will end all those annoying TPMS alerts and that you won't have to get your hands dirty topping up tire pressure any more. I nitro'd my Treg when the TPMS alerts became wearisome, and never touched a valve stem the rest of the time I owned it. Did my Cayenne last August, haven't touched it since.

//greg//

 

Where do you get Nitrogen? And how do you remove old fashioned air from the tire?

 

Varies with location. Logical place to start is where they sell (and mount) tires. I got mine at one of those quick oil change places. They have a system with one large nitro tank, four hoses, and a control box. Each hose is hooked up to a valve stem. The control box is set for the specified PSI of each tire, then subsequently bleeds the air and replaces it with nitrogen. Cost me $7 per tire, which included free adjustments for a year from the initial fill.

//greg//

 

An earlier discussion about this subject.

https://www.6speedonline.com/forums/...gen-tires.html

 

Some pretty nasty attitudes in that old thread. I personally don't care about the physics or the chemistry, I just appreciate that I no longer have to put up with the annoying TPMS alerts. That alone was worth the $28 bucks.

//greg//

 

And I appreciate the info

 

I have always heard mixed feelings about feeling tires with Nitrogen in the bike world, but interesting to hear positive results in a SUV.

 

Here is a informative clip that the show Fifth Gear did on there last show. Sounds like the source is very important.

http://youtu.be/knHeUF9JLzg

 

Interesting, but if they have an O2 sensor at hand why didn't they take a reading from the Nitrogen tires rather than just talk about the possibility of sub standard fills? I'm no fan of Nitrogen fills, but they could at least act a bit more scientific rather than just say it's scientific (take the O2 readings before/after, take temp ratings before/after, etc..).

Relatively speaking the units are cheap and start to realize a huge profit margin in a short period of time (even for a small shop that does a couple hundred cars a year). If you can make $20-$30 for the same work with no additional labor versus not getting anything (because people expect plain air to be free), which option would you try to get your customer to go with? Sure there are operating costs (maintenance and power), but they are almost always the same as the air systems.

I believe the scientific information about how Nitrogen reacts in tires, but that (profit) is the real crux of the problem for me and why I don't believe the hype for passenger tire applications. It's just another method for someone to try to line their pockets by emptying mine without any real benefit to me (my tires have always maintained their pressures for years without top offs and never had our BMWs TPMS annoy us when there hasn't actually been a problem).

 

this thread = false positive.

Nitrogen on a street car = Placebo.

 

+1....

 

Great points on this thread. Avogadro's law...
Save money for something else