Hey folks,

I always have my tires filled with Nitrogen, but with looking at my door placard, I'm lost. On my B7, it says...

H/V rated tires = 33PSI
Y rated tires = 30PSI

I have W rated tires (I don't really care what they are, but it seems common to only find W rated tires on the 235 45 17). I imagine I should be filling it to the Y recommended level.

But my question is...why do Y rates tires have less pressure??? It's just a tire?...

Vincent

 

you could have the same size tire by 2 differet manufactures both Y rating and have different PSI. Its where they recomend it based on their tires. I generaly put my tires at 30-32PSI regardless...yet my ties say 45PSI.

 

Why do people use nitrogen in their tires, what are the advantages and disadvantages?

 

Nitrogen holds better than oxygen therefore less fluctuation when the temperature dips.

 

I know nitrogen is an inert gas that will not expand or contract under varying temperatures. I just think that there is a current nitrogen trend going on and that its more of a money grab than a benefit. Air is made up of approx. 78% nitrogen, 21% oxygen and trace gases. So the air the we have been using for years in our tires is already almost 80% nitrogen. I believe to get the full benefit out of nitrogen filled tires you would first have to evacuate all of the air and trace moisture from the tire before filling with nitrogen and since garages can't do that then why are you spending the extra money? Now nitrogen molecules are larger than "air" molecules so in theory the contents of the tire will stay longer in the tire rather than leaking out but really how much longer?

I suggest that those who are considering getting in the nitrogen trend save your money and check you tires more often.

 

Mike I normally store my winter / summer tires at 40PSI.
When it comes time to install they have lost 4 to 6 PSI over the summer /winter
I will see what happens to my nitrogen filled summer tires over the winter.
So far over the last 6 months they have remained stable and I have not add nitrogen to them
If they loose PSI then good by nitrogen