Another Nitrogen in Tires Question

After having a repair estimate made on my Liberty by a Geico adjuster, we were discussing general car stuff. He stated that I should be running Nitrogen in my tires. He said he got 3 mpg greater mileage on his SUV by using Nitrogen.

So the question is, for those who have their KJ tires filled with Nitrogen, have you actually observed an increase in mileage?

I am not concerned about how long you can go between adding air, or the Nitrogen moleclues being larger or whatever. Just simply:

Does anybody have proof that they get better mileage using Nitrogen in their tires?

scoobybri said:

http://www.straightdope.com/columns/070216.html

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The article says it all....

Personally, I did not really notice a MPG increase. However, the fact that they stay at whatever level you fill them up at for longer, I guess you could say that yes you would have an increase in MPG. For example, I get my best mileage with my tires filled at 35psi. Since I bought them from Costco, I have them keep them at 35 when they do a rotation and balance every 6K.

It would be a total waste of time and money for me.In the summer months I'm dropping my psi to 12-15(for the trail) and then reinflating them to 38psi when I get off the trail with my PowerTank(co2) about 2-3 times a month.I can go on about 12 trails before I need to refill the tank(for $14) and co2 is also nonflammible.

12-15 psi???

richre1 said:

12-15 psi???

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Lowering your psi, especially if doing some rock crawling, will allow the tires to grip the terrain (rocks) better.

Not to get way off topic but yeah dropping down to 12-15 psi helps with offroad traction.The tire envelopes to rock for better traction.Here is a pic,look at the front tire enveloping that rock for maximum traction.

I drop down to 18-20 myself. I don't go lower than that because then the tire starts to sag and I lose clearance. In addition to better traction, it makes ride about 1000% better while hitting the trails by allowing the tires to absorb alot of the bumps, washboard, etc. When you're on the trail for 10 hours, you appreciate less "feedback" through the steering wheel.

2003KJ said:

For example, I get my best mileage with my tires filled at 35psi. Since I bought them from Costco, I have them keep them at 35 when they do a rotation and balance every 6K.

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35? I have air in mine at 33 (recommended by the chart) and have always been concerned that they looked flattish. Can I run mine at 35 as well with no problem?

Thanks!

ENBr said:

35? I have air in mine at 33 (recommended by the chart) and have always been concerned that they looked flattish. Can I run mine at 35 as well with no problem?

Thanks!

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I've run mine up to 40PSI. I don't recommend that because the tires start wearing oddly. Much quicker and go bald in the center.

I need to check, but I'm at about 35PSI right now.

What's the best way to determine the proper pressure when you change to a larger tire? I know I used to run the 235/70-16 Crapyear's at 35psi, but now that I'm on 245/75-16 BFG's should I up that?

KJ02Ltd said:

What's the best way to determine the proper pressure when you change to a larger tire? I know I used to run the 235/70-16 Crapyear's at 35psi, but now that I'm on 245/75-16 BFG's should I up that?

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Check the maximum on the tire itself. Then minus 5-10 PSI depending on your driving environment. I have a maximum load of 44 PSI. I run at 37.

This is not some formal way of running a bigger sized tire but it has worked fine for me. I might go down to 35 PSI though and see what kind of mileage/traction I get.

MoladoGuy said:

Check the maximum on the tire itself. Then minus 5-10 PSI depending on your driving environment. I have a maximum load of 44 PSI. I run at 37.

This is not some formal way of running a bigger sized tire but it has worked fine for me. I might go down to 35 PSI though and see what kind of mileage/traction I get.

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Sounds good. I'll take a look at it.

The old chalk test, from years ago still works. Run a heavy line of chalk across the tread and drive forward for about 100 yds in a straight line. Look at the chalk line. To much pressure the chalk will still be seen on the tread edges and more or totally gone in the center. Chalk in the center and gone on the edges, too little pressure. chalk gone evenly across the tire, you got it. I did this loaded and unloaded and wrote down the results and put them on the visor to keep me honest. A construction crayon I'm told also works.

CRD4Liberty said:

The old chalk test, from years ago still works. Run a heavy line of chalk across the tread and drive forward for about 100 yds in a straight line. Look at the chalk line. To much pressure the chalk will still be seen on the tread edges and more or totally gone in the center. Chalk in the center and gone on the edges, too little pressure. chalk gone evenly across the tire, you got it. I did this loaded and unloaded and wrote down the results and put them on the visor to keep me honest. A construction crayon I'm told also works.

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Makes sense. I've been wondering where to run mine at since I got them. Noticed that they're rated to 80psi max but, I definitely don't think I need to run them at 65, even. I have them at 38 right now. Rides quiet on the highway and seems to work pretty well off-road but, I haven't done anything more than play in some sand and ford a sandy/rocky creek with them, yet. Guess I'll have to give this a shot, thanks.

ENBr said:

35? I have air in mine at 33 (recommended by the chart) and have always been concerned that they looked flattish. Can I run mine at 35 as well with no problem?

Thanks!

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33 is for the size 215 tires, that's what my door sticker says. It doesn't even list 235 pressure. I also run 35 or 36.

I run my stock tires at 36 or so..

CRD4Liberty said:

The old chalk test, from years ago still works. Run a heavy line of chalk across the tread and drive forward for about 100 yds in a straight line. Look at the chalk line. To much pressure the chalk will still be seen on the tread edges and more or totally gone in the center. Chalk in the center and gone on the edges, too little pressure. chalk gone evenly across the tire, you got it. I did this loaded and unloaded and wrote down the results and put them on the visor to keep me honest. A construction crayon I'm told also works.

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Thanks for reminding me of that trick, I'd forgotten.

CRD4Liberty said:

The old chalk test, from years ago still works. Run a heavy line of chalk across the tread and drive forward for about 100 yds in a straight line. Look at the chalk line. To much pressure the chalk will still be seen on the tread edges and more or totally gone in the center. Chalk in the center and gone on the edges, too little pressure. chalk gone evenly across the tire, you got it. I did this loaded and unloaded and wrote down the results and put them on the visor to keep me honest. A construction crayon I'm told also works.

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I have a piece of that sidewalk chalk the kids use. Puts a nice wide line on the tire.

Dave