[DCBULLINGTON]

My last truck was a 2013 Silverado. My new ZR2 Duramax has N2 filled tires which I've never had before. I recently received an email from the dealer letting me know that my tire pressure was low (31 psi) on all four tires. They recommend 35 psi for optimum gas mileage and tire wear. So a couple of questions:

 

[DCBULLINGTON]

...sorry, fat fingered the "send" button!

I thought N2 filled tires did not change pressure due to temperature drops?

Does anyone operate with a different psi in your tires and if so, have you seen any effects good or bad?

I called the dealer and they said drop by anytime and they would top of the pressure, I just hope I don't end up playing the same yo-yo game I had to play when I was running regular air!

Dave

 

[MNTNBKR]

...sorry, fat fingered the "send" button!

I thought N2 filled tires did not change pressure due to temperature drops?

Does anyone operate with a different psi in your tires and if so, have you seen any effects good or bad?

I called the dealer and they said drop by anytime and they would top of the pressure, I just hope I don't end up playing the same yo-yo game I had to play when I was running regular air!

Dave

Nitrogen doesn't leak through the pores of the tire as quickly as plain old air since the nitrogen molecule is larger than the "average" molecules in plain air. It also doesn't expand as much when the tires get hot from driving since Nitrogen is dry and regular air has water vapor. The water vapor become a gas and expand more than the other gasses in the tire when heated. When the tires are just sitting there and the temperature drops, air filled and nitrogen filled will drop by the same amount. I just top mine off with plain old free air and when I got new tires, went with normal air filled. No noticeable difference.

 

[DCBULLINGTON]

Thanks MNTNBKR. Sounds like the whole N2 thing might me a marketing exercise as opposed to having a tangible effect on tire pressure/performance. I believe it is fairly expensive but not sure what a shop would charge to fill a new set of tires with N2.

Dave

 

[oak1971]

By volume, dry air contains 78.09% nitrogen, 20.95% oxygen, 0.93% argon, 0.04% carbon dioxide, and small amounts of other gases

 

[DCBULLINGTON]

By volume, dry air contains 78.09% nitrogen, 20.95% oxygen, 0.93% argon, 0.04% carbon dioxide, and small amounts of other gases

oak1971,

Sounds like the N2 filled tires thing is 78.09% bullshit!

Dave

 

[oak1971]

I have an air compressor, so the temp fluctuations don't really inconvenience me the few times a year I need to adjust. If had onboard air, it would just give me an excuse to justify another toy. Not seeing much downside.

 

[InfernoZ71]

DCBULLINGTON: Yes, agreed that nitrogen fill is not worth paying for a "20%" increase of nitrogen when the benefits are negligible. As far as the 35 psi cold temp setting you see on the drivers door pillar, that is the minimum tire pressure required for the vehicle to perform to its capabilities. I remember seeing that in the owners manual somewhere, I just cannot find the page at this time to reference for you. I typically keep mine around 38-40. As a note: The pressures change with temperature change, 1 psi for every 10 degrees. This can be due to ambient temperature change or due to driving. The friction between the tires and the road increases the tire temperature, therefore the pressure as well, so if checking a low tire after driving for a bit, pressure should be a few psi higher (like 3-4) than what ever cold pressure you set them to. Typically, most TPMS systems turn the light on around a 5-6 psi drop (there were also some older systems on some cars that would turn the light on if the tire was over inflated, imagine how angry those owners got trying to fill their tires just to get the light to turn off!!, Hahaha).