Nitrogen in tires
 

I keep reading where folks are paying to run 100% nitrogen in their tires on a street car. It is a rip-off and you are being taken (and most likely laughed at behind your back by the guy who just took your money).

The atmosphere is already 78% nitrogen with 20% being oxygen. Replacing the 20% might be a consideration for an F1 car that is looking for any way to eek out an advantage over competitors regardless of the cost, but to do this on a street/DE car is a colossal waste IMO.

Feel free to chime in, I can tell you what the shop guys are saying about you because I have spoken to them. Spend your money on something other than the king's new clothes.

Land, speaking only for myself, the car I bought had it converted, I have zero intention on continuing to use it, especially since I own a compressor.

I just hate to see an industry (tire stores) perpetrate a ruse on the public. I was at a friendly competitor's shop and he had a shiny new nitrogen generator there. He wants to increase his bottom line, the equipment reps are pushing it hard and the public is being ripped off AGAIN. I won't do that crap in my shop.

Also how do you know the gizmo is changing the gases at all?

The same leap of faith you make when you press 94 octane from a pump that can dispense 89.

Just like bottled water...

http://www.michaeljaylissner.com/fil..._0.preview.jpg

I have always wondered, but spoke to a state inspector and they do random test for octane rating. After talking with him I am fairly sure I am getting what I pay for. However per his words there are so many stations and he has to inspect them all. So a recently inspected one has a clear window of one to two years before they can expect a suprise visit.

I have noticed that some synthetic oil has a foil top under the cap and some does not. I would not put it past a few parts stores that have fallen on hard times to put dino oil in place of the much pricier synthetic. I need to study the brands and I will post which has foil and which does not.

I had my last set of tires replaced and filled with nitrogen at no extra charge by the car shop. Since it was no big deal, I didn't have an opinion one way or another. I have been in the habit of checking my tire pressure and re-inflating my tires every two months over the last year.

Since then, I have noticed that my nitrogen-filled tires hardly lose any pressure compared to the tires on my BMW which are air-filled, which tends to lose 2-3 psi every two months (on the same checking interval).

FWIW, it seems the nitrogen filled tires are definitely having a positive impact.

Over the course of a one-year study using 31 different tire models, Consumer Reports found that the tire pressure in a nitrogen filled tire was maintained by 1.3psi more than an air filled tire. That is an average difference of 0.1psi per month between nitrogen and air. Unless you're racing and maintaining tire pressures to within +/- 0.5psi you'll never notice this difference in tire pressure stability.

Of course, your particular mileage may vary (different tires/wheels combinations along with differing wear will result in varying tire pressure stability), but nitrogen filling is generally worthless in the aggregate.

Reference: Tires - Nitrogen air loss study

If the balance of the gas mixture were 22% O2, that would be fine with me, but what I find at most gas stations is that the "air" is a 50/50 mixture of water and air. OK, a little exaggeration, but it's my experience that water corrodes aluminum at the bead resulting in slow leaks. I've had to have tires dismounted on the Fuchs wheels of my 914-6 to prep the surface. As for my boxster, I put serious money into forged 3 piece wheels. I don't want to find out what water would do to them. The cost of N2 is small compared to all the other nonsense things we buy for our cars.

Air from any shop that uses air tools will have a dryer and be perfectly acceptable. I can't speak for those quarter machine though.

I love the sales pitch for Nitrogen filled tires: It's what NASCA, F1 and airplanes fill their tire with! The reason those organization fill with nitrogen is two fold. Yes nitrogen is more stabile and consistent than air and secondly - more importantly - when the tire catches on fire, the nitrogen doesn't feed the fire like straight air would.
So the primary reason is safety.

How about HYDROGEN??????

Just kidding. Glad to read a thread with a bunch of guys contributing that have good sense.

The key is DRY AIR. In general, nitrogen filled tires have a dryer air content. Dry air means a greater tire pressure consistency over a wider temperature gradient.

I like the nitrogen filled tires for winter storage (55-58 PSI). I bleed the excess air in the spring prior to the first drive of the season. Bleed a little bit more as temps increase with the summer driving season (for about every 10 degree temps change, tire pressures move 1 PSI, assuming dry air). My tires pressures are very-very steady and consistent throughout the driving season. In late fall, when air temps start to plummet, I only require a couple tire pressure adjustments (then I use good, normal, dry, shop air).

Prior to winter hibernation, I over fill again with nitrogen, never charged, I just throw the kid at the tire shop a $20 tip, and drive the 6 block home very slowly. During the winter hibernation period, 4-6 months (depending on which car), the over filled tires might lose 1 PSI. Again an advantage.

Works for me the past 5-6 years.

Again, the key is dry air.