dTor

iTrader: (27)

I switched from air to nitrogen in my tires September of last year. Specs:

'03 G coupe, automatic, currently 87k miles
headers
true dual exhaust
3.5 vlsd pumpkin swap

I religiously check my mileage. Everytime I fill up, I check my mpg. Before switching to nitrogen, I would get 17-19 mpg combined city/hwy, and 22 mpg all highway.

The day after I had nitrogen put in, I drove to Atlanta, about 7-8 hours drive. All highway, I got just over 26 mpg. No BS. This was driving during the day, with the A/C running all day long, cruise set to 73 mph (anything over that and the cruise will kick off because of the different gear ratio).

The first thing I noticed as soon as I drove the car was that small, harsh bumps in the road did not feel quite as harsh as before. This was not something I was told about prior to getting nitrogen put in nor something I would have expected, so I know it is not a placebo effect. Speaking with other people who have recently switched to nitrogen, they told me they experienced the same thing.

As far as longer tire life - I don't know yet. I just switched tires 3 weeks ago, but I got about 22k miles out of my previous Nitto NT555, and they still had quite a bit of tread left on them when removed (I changed them because their wet traction is teh suck).

As far as combined city/hwy, I get about 20-21 mpg, depending on how much city and how much hwy driving is involved. I just drove from MS to Corpus Christi, TX today. I got 427 miles on my first tank, having to stop in Houston to fill up. It was only 16.15 gals when I filled up, so I could have easily gotten over 450 miles on one tank. I got 26.44 mpg on this tank. Keep in mind this is on an auto with a lower gear ratio - I'm turing 2700 RPMs at 70 mph. A regular (3.3) diff on an auto may get you slightly better mpg, but ymmv.

I am not a physicist, and I am not going to do your research for you. If you don't know how or why nitrogen does better than air, then is your friend. If you just want to talk trash about this being a gimmick, then you, my friend, are sadly mistaken. I have been running nitrogen for almost a year before I made any judgement, but my results have been consistent each and every time I check my mileage, and they are consistent with what other people I've spoken with who made the switch have observed.

300zx1985

iTrader: (8)

I get my nitrogen at Butler Tire here in Atlanta. Cant say how much of a difference it makes but I want the best for my cars.

ANXIOUZ

iTrader: (13)

How good were you before nitrogen about checking your tire pressure regularly? I can see you having more consistent #'s over a long period of time with N but that's about it. It's not going to improve mpg all that much unless you were under-inflated previously.

flynbrin

iTrader: (29)

hmmm

better look for some nitrogen

nice post

dTor

iTrader: (27)

Very good point. I can't say I checked weekly, but about once a month I would add one to three pounds when I was running regular air. My mpg #s didn't fluctuate greatly between checks - at least not enough to notice a change in mpg. My overall mpg with air was my average over a 1 year 3 month period - I bought the car 6-6-06 , and switched to N in September 2007, the Thursday before NOPI Nationals.

JETPILOT

iTrader: (51)

Nitrogen is BS. Air is 78% nitrogen. When you get your tires mounted the volume of the tire is fileld with air. Unless you pull all the air out of the tire with vacuum then you already have one atmosphere of air in there which will mix with the nitrogen fill anyway.

dTor

iTrader: (27)

This is true. Like I said, I'm not a physicist, and I can google just as easily as you can. There's great reason why it's used in the tires of the jets that you pilot, though. Do you know what it is?

JETPILOT

iTrader: (51)

High altitude airplane tires are filled with nitrogen due to the temperature extremes high altitude airplane tires see. Nitrogen does not expand or contract very much with temperature change. So When I descend from 36,000 feet where the air in my tires is approx -40F my tires have the correct pressure on landing. The air in the tire will not get warm enough during my descent for the tire to be at operating pressure when I land if I used air. In addition. When I land my tire temps shoot up from friction, and brake heat. Again with nitrogen my pressure won't change in any meaningful way. The temp changes seen in street car does not warrant the use of nitrogen. It's a waste of money. All marketing. Sorry!

davidv

iTrader: (2)

I trust every fact in your sorry. Relating those observations to nitrogen is a different story.

davidv

iTrader: (2)

Yes. The aircraft is flying at 70,000 plus feet.

dTor

iTrader: (27)

I can't tell you how many pilots (I'm in Army Aviation maintenance) have no clue, nor care, why some basic maintenance items are performed on "their" choppers.

Maybe some other people can chime in on this who have made the switch. Like I said, I'm posting my personal results that I've studied for about two years. I know there are varying opinions, and that's good. I'm not here to try to convince anybody of anything.

Anyway it's time for bed. I'll check back tomorrow.

dTor

iTrader: (27)

SR-71 Blackbird is my wife's favorite jet ever. Awesome looking aircraft.

davidv

iTrader: (2)

I assume that 100 percent nitrogen has a low (1 percent) water vapor content. Similiar to aviators breathing oxygen.

JETPILOT

iTrader: (51)

I however do see a good use for nitrogen in race cars where you also want to keep optimum tire pressure which will not change when the tire heats up to operating temp from friction and brake heat. But for street cars I just don't see any advantage.

In order to get a good fill of nitrogen for your track tires pull the valve out of the stem and fill the tire with nitrogen after mounting. Let the nitrogen out of the tire. Do this twice. Reinstall the valve in the stem and fill the final time with nitrogen. This will purge the vast majority of air for a good fill of nitrogen.

350ZTheStandard

iTrader: (4)

whatever people, you can get Nitrogen at your local Costco

flynbrin

iTrader: (29)

when it comes to cars, i guess nitrogen is pretty much a bust

badkarma85

iTrader: (1)

It cannot possibly be a placebo if you were told about it, so your argument is wrong.

A placebo effect occurs when you were not told about it. So in fact, it was a placebo.

While I don't believe in your actual findings, I believe in a good placebo.

You may subconsciously drive slower than before, causing the mileage to improve. There are also many other factors that come into play..

Also, it's been scientifically proven that placebos work, not in its own capacity but coupled with the positive reinforcement of the mind and subconscious efforts, the effect produces positive results. i.e. cancer patients who take glucose pills and were not told what they were, believed that they were getting better and considered these tables to be miracle pills. Drawing from very basic knowledge of oncology, we know that there's no direct relationship between glucose tablets and reduction of cancer cells.

Placebo effect.

ARMSTRONGARMS

iTrader: (65)

WAT sounds like hot air to me?

terrasmak

iTrader: (8)

Or use Nt03's with duel valve stems.

davidv

iTrader: (2)

Thanks Sigmund.