I got an '08 6i sport value in May and love the car. who has nitrogen tires here? I just had them filled up last week for the first time and the light came back on yesterday. can I buy a regular air pressure checker or do I have to buy one for nitrogen? if there is one

 

I would think a regular gauge is fine. However, you might as well let the shop do it as they will need to top off the nitrogen anyway.

 

I don't know if a regular PSI meter would be able to read the pressure because it measures in atmospheric pressure (KPa is another measurement of air pressure, like PSI). Then again, the atmosphere is ~78% nitrogen, so you may get an accurate reading.

What is the appeal of filling your tires with nitrogen anyway? All I've heard being done is seriously inflating the tires, to crazy levels like 50PSI on normal series tires (e.g. 205/60R16). With that much air in the tire, would the sidewall even be able to flex and would the tire grip? Regardless of the claimed increased in MPG, I would never endanger myself by making my car's handling poorer.

Maybe Richard will pop in, he probably knows more than I do.

 

well the car came with these tires. but it handles fine, wet or dry. and cornering is good too. and I just filled the gas tank the other day and I'm gonna figure out the mpg and possibly compare it to some of ya'll with air filled tires, just out of curiosity

 

I'm not saying you've got poor handling tires, I'm saying that I don't know how 100% nitrogen will affect the tires, especially at such high PSI - the reason they jack up the PSI is so less of the tire contacts the road, and there's less rolling resistance, which equals better MPG in theory.

But at such a high pressure, I'm worried the sidewalls won't flex during cornering, and not enough of the tires' surface area will contact the road, thus = less grip. Add to that solitary contact of the middle of your tires will cause them to wear much faster there...unequal wear can cause unpredictable grip. Then you have to buy new tires...so really, where's the saved money in gas going? I think the whole schtick's a ploy, personally. But still, I'm interested in the results you get.

 

Here's what I have read:
1) It contains no moisture so filling your tires with pure, compressed, "dry" nitrogen reduces derogation of the rubber (rot) from inside the tire where it usually begins. Of course this can also have a positive affect on wheel material too.
2) It is more stable across a wider temperature range, so there is less of a pressure change between a hot tire and a cool one. (e.g. 1lb vs. 3-4lbs.)
3) The molecules are physically larger and therefore are less likely to pass through the porous metals such as aluminum or magnesium compounds, or the tire itself.
4) Some claim their mileage increased when they switched to nitrogen, while others disagree and claim no mileage increase.
5) While not absolutely necessary, ideally it is best to have a wheel designed for nitrogen/inert gas useage. A second valve stem that acts as a vacuum port to pull the air out and monitor the purity of the nitrogen in the tire. This requires special equipment designed for this purpose. A machine with a pressure side, a vacuum side and a monitor.
Here is a wheel that is designed for inert gas usage. Note the twin valve ports on either side of the wheel:

 

yep, that's basically it. I'm just sayin I'm not too impressed as the dealer made it sound when he was selling us the car. I mean if I have to go all the way to the dealership everytime that warning light comes on, I'm gonna see about getting regular tires when that time comes. and I'm sure it might be hard because there's sensors on all 4 tires and sends an alert to the electrical system basically tellin me...fill me up! eventually I wanna buy 18's for it, would I have to find some special rims like above?

 

Gina, it's not the tires that are different. You can change to, or add compressed air any time you want to. It's just the medium, in this case nitrogen, that is used to fill them.

I own a set of those wheels I pictured above, but run compressed air in them. I too have wondered whether or not is was worth the extra hassle for what is essentially, my daily driver.
(My car with 17x7" Kosei Racing wheels in Med-Gray, "Graphite"... not the best picture)



Perhaps if I owned a highly-strung, expensive sports exotic that I raced every weekend, I would be more concerned about what gas I ran in the tires, but frankly to me it's just not worth it.

 

alright, cool. I was worried about if there would be any hassle with the electrical system when I get new tires or rims, whichever comes first, but you've helped me understand more now

 

Richard,
Is that a Chevy Cavalier you are hiding beside your Mazda? If so your not doing a very good job! lol

Vince