pressing nitrogen or nitrogen on the tires

If friends are aware of this incident or have done this job, I would be glad if they share their experiences.

As far as I know it is lighter than air, it makes the difference of walking fuel even though it is very small and it also extends the life of the tires.

I heard that when nitrogen is pressed, it makes the vehicle bulky and affects its course.

My wheels are nitrogen.
Tires are more flexible. It also gets warmer later on the long journey. This increases tire life.
In addition, since nitrogen is lighter, some benefit in fuel (muş).