Wednesday, June 11, 2008

Fuel Economy Series Part 3

by Tim Joseph

Last November I got a couple of my tires replaced at our Nissan dealership. I said to the tech who did the work, "Why don't we put Nitrogen in the two front tires and air in the back two?" We both thought that'd be a fun experiment. After a very very cold winter and now a very warm spring I'm happy to say that the Nitrogen held up very well. A lot better than regular air. I've since filled the back two tires with Nitrogen but I have to ask myself.. what is it about this nitrogen that makes it better? How does it keep the tires inflated longer? Why is that important?

In researching this blog series I have read countless tips and tricks to get you the best gas mileage. One thing that every website out there agreed upon was the need to get your tires properly inflated. Nitrogen has become the gold standard in tire inflation. Because it has more mass, it migrates through the tire 3-4 times slower than compressed air. Also, it runs 20% cooler than air which leads to less tire degradation.

On average a tire filled with air will lose 2.7 psi per month. Nitrogen filled tires will only lose about 0.7 psi per month. This is a significant difference in tire pressure. When your tires are not properly inflated it is like driving your car through sand. The engine has to work harder and you use more gas. Nitrogen will also have you money on tires. 15% under inflation will result in 8% less tread mileage and 2.5% degrease in fuel economy.

According to a Nitrogen Savings Calculator I found, I save $208 a year with nitrogen in my tires. That made the $3.75 per tire charge well worth it.

Right now, Dick Scott has a fuel saver special - 27 point safety inspection, oil change, nitrogen inflation in all four tires for $29.95.

Dodge - 800-571-6906
Motormall - 800-486-2415
Kia - 800-730-9872
Nissan - 800-504-8536