Fuel Economy Tip - Fill Your Tires With Nitrogen?
August 3rd, 2006 | by Brian Carr |Today’s tip will hopefully help you increase your car’s fuel economy by 1 to 2%. While that may not seem like much, over time, it’ll definitely add up (assuming this theory is correct).
Fill your tires with pure nitrogen as opposed to filling them up with “regular air.”
The last time I had the tires changed on my car (which was a week or two ago), when I got the receipt back, I noticed a small additional charge for filling my tires with pure nitrogen. I didn’t really think much of it at the time, but a few days later I decided to do some “internet investigation” and find out why I was driving around on nitrogen filled tires.
As a side note, yes, I realize I could have just called the tire place, but that would have been too easy.
Anyway, what I found out through my research (here’s one site I found) is there is a belief that tires filled with pure nitrogen tend to hold proper tire pressure longer than tires filled with regular air. The theory behind this is because nitrogen molecules are bigger than oxygen molecules, thus less likely to escape the tire.
To be honest, I haven’t really noticed much of a difference, but maybe a month down the road when I go to check my tires, I’ll be pleasantly surprised to see that my tires have held their pressure.
So, for the time being, I would recommend that if you go out and get a new set of tires in the near future, go ahead and spend the couple extra bucks to try it out. If it doesn’t work out, you’re not going to be out much, but if it does work out, you stand to save some gas and money.
3 Responses to “Fuel Economy Tip - Fill Your Tires With Nitrogen?”
By Pal on Jun 8, 2007 | Reply
“Pure air” is 78% nitrogen already, with just 20% being oxygen. If a person thinks that the pure nitrogen injection is the magic bullet for ignoring their tire pressure they should reconsider. You should always check your tires when getting gas, and inflate tires that will naturally lose pressure over time.
Show me a test where a tire is inflated with “normal air”; after running the car for a few weeks on a dyno or around town to allow the tires to lose some pressure, the tire is vacuumed out; the gases pulled out are tested and shown to have noticeably more nitrogen than oxygen, compared to normal air. I seriously doubt such a test has been done by any credible source.
This is really just another way of admitting to a sales person that you can be swindled out of money with fancy words.
By William Wilgus on Jul 9, 2007 | Reply
The advantage of nitrogen as a tire inflation gas is that it does not expand or contract with temperature changes. Theoretically, then your tires would always be at the recommended pressure. The advantages to this are that the tire does not expand when heated—increasing the life of the tire—and the tires’ road-holding properties remain more constant. This latter advantage is only important in racing or high-performance driving, or course.
Regardless, simply adding nitrogen does little good if you don’t evacuate the air from the tire first—or during the process.
By Bob Matiska on Jul 26, 2007 | Reply
Nitrogen doesn’t expand when heated nor contract when cooled? Sure it does, just like all other gasses. And nitrogen, with an atomic number of 7 and an atomic weight of 14, is larger than oxygen, with an atomic number of 8 and atomic weight of 16? Since when?
OK, somebody here do us all a favor and buy 4 new tires, then have two inflated with air and two with nirogen. Keep track of the pressures with a good gauge for a few months and let us all know how the pressures hold up.