Nitrogen in tires - worth it?

[rcy]

What's next? Helium to make the car bit lighter?

As a lot on here are hinting at, just check your tire pressures regularly (don't depend on the TPMS if you have one) and motor on.

 

[Lurch]

Actually I've improved my opinion of Nitrogen. I just stopped in to the tire place I got the Nitrogen at (as well as my tires a few years ago), and the rear tires had 42 PSI in them, and the front had 35 PSI. He said I should be good until cold weather gets here. He said cold weather makes them go down, and if more is added, it will have more than enough Nitrogen when warm weather returns.

I guess it's all about learning how to deal with it, but if I can now go several months w/o having to fool around checking my tires, I'll be happy. If the car handles good and the tires looked formed at the bottom, I'm probably in good shape. IMHO it beats having to check PSI/add air every week, or 3 weeks, or whatever.

Joe

 

[ddombrowski]

I've commented on nitrogen enough times that usually I don't bother, but an interesting thought just popped into my head.

When you install a new tire on a rim, you drop the tire on and set the press that folds the bead over the edge (real technical terms, I know) and rotate the assembly around. Then, when the tire is on, you fill the tire with air/nitrogen to set the bead into the rim, right?

The compressed air line to the machine is singular - they don't have 2 lines labeled "Good air" and "Cheap air". Cost benefit aside, whether or not you pay for nitrogen, you're getting the same thing. I found this funny. Same thing with the additional sticker on the window of new cars - Nitrogen for $XX. Do you really think they took the cars off the delivery truck, drained the tires, and then refilled them with N2? I'm positive they didn't. Either they already had it from the factory, or you're paying for a non-existant service.

Okay, that aside, yeah, I'd never pay for it. Dry nitrogen does have the benefit that you can set your cold tire pressures higher and maintain the same hot pressure, thus having a more properly inflated tire while cold, but its not something I would pay for.

The guy at costco lets me fill my portable tank with N2 whenever I stop in for gas or tire rotations, so I use it. If they ever wanted to charge me or told me I couldn't, it would be the last thing on my mind to worry about.

 

[Kestas]

You forgot to mention the water-based lube they use to mount the tires. Where do do you think that water goes once the tire is mounted? Yup, right into the dry air inside the tire! You'll probably still have condensation inside the tire during winter.

The fact is that nitrogen-filled tires lose pressure at a rate that is 60% of air-filled tires. This is from the only controlled test that I know of where the tires were tested over a year's time (Consumer Reports, JAN '08). But you still have to check the air and top off as needed. If you think it's worth the slower leakage, fine, go ahead with the trouble and expense.

 

[scurvy]

Originally Posted By: Kestas
The fact is that nitrogen-filled tires lose pressure at a rate that is 60% of air-filled tires. This is from the only controlled test that I know of where the tires were tested over a year's time (Consumer Reports, JAN '08).


Just to put some actual numbers to it, 31 pairs of tires were split. One of each pair was filled with air, the other filled & purged with nitrogen 3 times which resulted in 95% pure N2. Both inflated to 30 psi indoors. They were all set outside for a year. Then brought back indoors to equilibrate and their pressure checked.

Air inflated tires lost an average of 3.5 psi (std dev 1.6 psi) over a year. Nitrogen inflated tires lost an average of 2.2 psi (std dev 1.2 psi). 1.3 psi difference over a year - that's all.

CR's test report is here if you're interested.

 

[sbergman27]

Originally Posted By: scurvy
And according to a Consumer Reports' data study (not an opinion study) there was very little difference in pressure loss between the two - only 1.3 psi difference over a year from an initial fill of 30 psig.

Which suggests that nitrogen-fill is more likely to lead to overconfidence and running on low pressure in the event that a tire develops any sort of slow leak, since the owner doesn't think he needs to pay attention since... they are nitrogen-filled, after all. I wonder what a study along those lines would find?

 

[Audi Junkie]

I invented nitrogen.

 

[XS650]

Originally Posted By: Audi Junkie
I invented nitrogen.


Nitrogen doesn't burn when you light it with a match.