OK, there are a couple of threads about this, but probably worthwhile to create a new one. I got my regular oil change in my 2005 Package #6 a week ago, and found that my normal service place has added a nitrogen filler to their shop. Figured that the $30 expense was worth trying once, but didn't expect any serious changes out of it. Pumped the tires to 42 PSI. Surprisingly, on the first tankful, I averaged just under 8 mpg higher for the same type of driving (same basic route, same area) per the onboard computer. I live at high altitude, and rarely get more than 43-44 mpg, although this improves if I go to a lower altitude (like the SF bay area). Still, this latest tank was 51.6 mpg. Was it a fluke? I don't know, but am watching this second tank closely and seeing similar results so far. Has anyone else tried this and tracked their improvements? Post your results here! Dan
I'm at a loss to see how this would help your mileage numbers. The use of nitrogen is promoted as a safety feature, because there is no oxygen to degrade the tires or oxidize the wheels. There also is some anectodal evidence that tires filled with nitrogen (at 95% nitrogen, vs. the 80% nitrogen that you get when filling your tires with air) will hold pressure longer. This would lead to fewer blowouts from overheating, I'm certain, but the better bet is simply to check tire pressure regularly. Is it possible your increase in mpgs is related more to warming air temperatures than anything else?
That makes two of us. I did get the oil changed the same day, which could account for a bit better mileage (but hasn't really changed it significantly in the past). They didn't replace the air filter or do any other work, so it was just oil and nitrogen (and probably more washer fluid, if you want to get picky!). I don't know how full the tires were previously, though... they may have been less that 42 PSI, and that could have caused a change. Weather differences, though, aren't likely, as the weather and overall temperature were about the same between the two most recent tanks. Planning to watch the next few tanks closely, but if anyone else has tried this and noticed a change, I'd like to hear about it in this thread. Dan
Thank you! There may even be more of us around! This seems a more likely culprit. It very well could be that your tire pressure had started in teh low 30s and dropped, if you weren't checking it regularly. Many people report increased MPGs just from raising the tire pressure. I've set mine pretty high, and I think it helps. And I'm just using 80% nitrogen, not the 95-100% stuff.
I have been using nitrogen in my tires for a couple of years and, speaking from only my experience, a statistical pool of 1, which may not be very accurate, found that there is a much slower rate of bleed down of tire pressure. So slow that I am only loosing a pound or two between rotations/balancing each 5k. It was so good that I tried it in my bicycle tires....but alas, not as much of a benefit there.
There is no causal effect whatsoever, nor can there be due to simple physics. Look elsewhere for your mileage gain, perhaps increased tire pressure or warmer weather. Tom
I have used N2 since my first day almost 2 months ago. TP is exactly what it was the day I left the lot. Im boosting it to 42 or 44 when I have my first service. If it's good enough for all the airlines, military, nasa, and nascar; I fail to see why you guys are so tuff to please!
I use N2/02/junk (air), and I've been able to maintain great tire pressure. I had a noticeable drop in only one tire across a four-month stretch of winter. I think having higher pressure on the tires also makes it easier to maintain that pressure, but that is a "pool of 1" survey, as well. I'm not too worried about damage to the tires from oxidation. I'll likely lose tread before the tire starts deteriorating. We are not trying to extend the lives of exceptionally valuable tires.
One thing people often don't think about is the difference in tire/air temps when they are checking pressure. If you set your pressure while the tire is warm and ambient temps are in the 80s and then check the pressure again two months later but the tire is cold and ambient temps are now in the 50s you should expect to see a difference and this may not be attributed to bleed off. Reverse this scenario and if temps are lower then you may indeed observe some bleed off but without exact data on tire and temperature conditions it's hard to be sure.
One wonders if the gauge where you checked your tyres with air was reading high so now you actually have 42 in your tyres for the first time?
Hello all, just bought an 08 and still on the first tank. 49.7 so far and loving it I just wanted to chime in on the nitrogen chat. As a former aircraft mechanic and now pilot, the reason we use nitrogen is because the molecules are less affected by temperature. So, when you touch down or takeoff and the tires heat up and expand - they won't explode as normal air would cause them to do. The only benefit I see from using nitrogen is less fuss with tire pressures as the outside temps change. Other than that, 42psi is 42psi no matter whether it's mut air or pure nitrogen. I would definitely use nitrogen if I had it and it was free. So I'm stuck with the cigarette lighter tire pump for right now!
This is just plain wrong. Nitrogen expands every bit as much as any ideal gas. It also diffuses a tiny bit faster than oxygen, so pure Nitrogen will diffuse through tires a bit faster than air. Perhaps you are confusing the expansion characteristics of water vapor, which is a non-ideal gas. Dry Nitrogen contains little water vapor, but then dry air would be the same. Tom
Density of humid air fluctuates more with temperature than that of dry air, so removing humidity (using nitrogen) can keep your tire pressure more consistent, especially when the temperature climbs over 100 degrees Fahrenheit.
Nitrogen in Tires : Information about Nitrogen Tire Inflation News, Benefits, Generator Dealers, Location Finder & More an offical organization promoting the use of N2 in tires for safety and conservation of fuel. They do the math and list a lot of schools and universities that have tested and found N2 to be a better alternative to air.
This is an organization that makes money by promoting Nitrogen for tires. The information is mostly worthless. Tom
This is true, as I pointed out in the earlier thread. That said, most tire shops do not use dry nitrogen from a dewar, but instead use a "nitronizer", which is a gizmo that increases the concentration of nitrogen in ordinary air. Water vapor is removed or reduced by a desiccator, just as it would be with a good air compressor. Using this system, there is no advantage other than making money for the tire shop and the company selling "nitronizers". We've been through this many times before. Here is a link to one of the previous threads: http://priuschat.com/forums/fuel-economy/34481-nitrogen-prius-tires.html Tom
And Henry Ford made money from the sale of his Model A and T. Because he made money does that make the automobile worthless? How about medical drugs for all sorts of illnesses. They make a profit, so does that make them worthless? If something has value it is worth promoting and making money. The Prius cost 23K plus. By your logic that makes it worthless too I guess? name me one thing you find of value that has not made money for someone. Nasa uses N2. Nascar uses it too. are they wrong?
