Nitrogen in Tires

[john burns]

My last Hybrid was a 2005 Honda Civic Hybrid

It was one of the best cars I ever owned (tied with my Subaru Outback). I switched to the 2010 Prius because I liked the technology

My Honda, with nitrogen filled tires used to get an average 50 MPG. I determined nitrogen gave me about 2 more MPG

I did not have the Toyota dealer put nitrogen in the tires because I felt his prices were to steep, and he wanted to include the nitrogen with a package I was not interested in getting

I have a little over 1,000 miles on my new Prius, and am getting about 55 MPG

Plan on having the tires filled with nitrogen tomorrow and am anxious to see the difference in mileage

Any predictions?

[David Beale]

No difference.

[qbee42]

Nitrogen in passenger car tires doesn't hurt anything, but it doesn't help either. This topic has been extensively discussed many times on PC. Give it a search if you want the gory details.

Tom

[Politburo]

No difference. There are so many things that affect MPG, it is practically impossible to determine that a 2 MPG swing was due to just one factor, unless you're doing detailed testing like bwilson.

[BBaggins]

The primary benefit for mileage is that nitrogen is much less affected by tire temp. changes. Constant proper inflation is good.

Thirty years in the commercial aircraft field, ALL our aircraft tires were filled with nitrogen.

[qbee42]

Originally Posted by BBaggins

The primary benefit for mileage is that nitrogen is much less affected by tire temp. changes. Constant proper inflation is good.

Thirty years in the commercial aircraft field, ALL our aircraft tires were filled with nitrogen.

Nitrogen is affected by temperature in exactly the same way as all ideal gases. It is a common misconception that nitrogen is somehow immune from the Ideal Gas Law, but it is not and behaves almost identically to normal dry air.

There are good reasons that nitrogen is used in the tires of commercial aircraft. None of them apply to passenger cars:

1) Nitrogen is easy to transport onto the ramp as a cooled liquid.

2) Nitrogen gas expanded from liquid nitrogen is inherently dry. Commercial aircraft flying at altitude are subjected to extremely cold temperatures. At these temperatures, moisture inside the tires can condense and freeze, leading to server imbalance when landing.

3) Commercial aircraft tires are subjected to extreme conditions during landing. Nitrogen does not support combustion in the event of a tire fire.

Tom

[codybigdog123]

...not to mention that air is 78% Nitrogen.

[dogfriend]

W/O Nitrogen - 55 mpg

W/ Nitrogen - 55.000000000000000000001 mpg *
















* Your mileage may vary.

[qbee42]

Originally Posted by codybigdog123

...not to mention that air is 78% Nitrogen.

...and at no extra charge...

Tom

[wvgasguy]

Air is mostly nitrogen anyway. Now if you put helium in there I might understand it. The "lift" from the tires wanting to float should make the car "lighter".