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 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.

 

do all tire shops carry the gas or only select few?

 

When I first got it done last year, there was only one or two places in my city that did it. Now I think almost all of them have nitrogen.

It costs $7.50/tire around here. I made my money back in gas savings after the third fill-up.

 

Complete BS, this coming from a chemical engineer. Air is already 79% nitrogen, not even the nitrogen advocates would claim that it improves gas mileage 4 mpg . This is also coming from someone who also uses nitrogen. I use it because I don't lose as much air between pressure checks, and its free at my local tire shop. I got ZERO mileage improvement, and no difference in road feel.

 

 

IM with LUDE, lol. $ mpg sounds very excessive, **** any miles per gallon sounds excessive

 

Did you ever compare air to Nitrogen as fas as the ride quality?

 

Yes, no noticeable difference at all.

 

i think all you did was drive slower LOL, this is also coming from someone with a Nuclear Science degree, i get 25-27 mpg on the highway anyways with a/c and all...

 

The pure nitrogen air in the tyres is, as far as I am aware, a benefit in that it does not have the moisture associated with regular air. Plus, it doesn't leak as much as regular air anyway, (at least the oxygen/carbon dioxide/noble gasses).

 

what about pressure diff between hot and cold tires.

 

On the highway, I always set my cruise control, even on my daily trips going to work. I really love my cruise control, and I use it as much as I can. Like I said, if I exceed 74-75 mph, it kicks off because of my pumpkin swap, so I don't ever set it higher than 73.

Trust me, if I could drive faster, I would be, but at least it keeps me out of getting tickets.

Also, what are the specs on your car?

 

my cruise control stays on up to 92mph

 

um op obviously you get more mpg on road trips. i average 18 mpg city/highway but i got 23 mpg driving back from north carolina to florida. reason was cruising at steady rpm's not because i inhaled nitrogen ha.

as far as tire pressure, i can go thousands of miles without a drop only if the temperature changes or i push the car real hard.

90mph is actually the top of cruise, ours speedometers are just inaccurate. also why people try and say they did over 155mph stock LOL.

 

yea i assumed it was 90 lol i just like to say 92