What to fill inside of the TIRES?

Filling of the Tires

As we know, there are many fluids which we can fill inside of the tires. Most common filling fluids are as follows:

1. Air
2. Nitrogen
3. Water (Ballasting of  the tire)

Most commonly used fluid to fill tires is air. Comparatively, air is cheaper than the nitrogen because of easy to collect and fill. Then another most common fluid is nitrogen because nitrogen has some advantages over the air filled tires. There is also one more fluid used in the vehicle tires is water, which is known as the ballasting of the tire.

AIR and NITROGEN: 

Air filled tires are the most common type of fluid used in the tires. The main reason behind that is availability and cost of the air. Comparative to other fluid, air is the most easily available fluid and also available in large amount.Air is 78 percent nitrogen, just under 21 percent oxygen, and the rest is water vapour, CO2 and small concentrations of noble gases such as neon and argon. We can ignore the other gases. The war between air and nitrogen is from a long time since when nitrogen became the greatest technological invention has been invented i.e. since from technology invented as nitrogen is separated from air. Air doesn't have any special characteristics over nitrogen, but also nitrogen has some scientific advantages over air. Nitrogen is commonly used for aeroplane and race car tires. Racers figured out pretty quickly that tires filled with nitrogen rather than air also exhibit less pressure change with temperature swings. That means more consistent inflation pressures during a race as the tires heat up. And when you're tweaking a race car's handling with half-psi changes, that's important. Passenger cars can also benefit from the more stable pressures. But there's more: Humidity (water) is a Bad Thing to have inside a tire. Water, present as a vapour or even as a liquid in a tire, causes more of a pressure change with temperature swings than dry air does. It also promotes corrosion of the steel or aluminium rim.

Advantages of nitrogen over the air are as follows: 

1) Under-inflated tires can lower gas mileage by 0.3 percent for every 1 psi drop in pressure of all four tires. The theory is that since nitrogen loses pressure at a slower rate than air, you are more likely to be at the correct psi and therefore get better fuel economy. 

2) Over time, a tire will gradually lose pressure. Changes in temperature will accelerate this. The general rule of thumb is a loss of 1 psi for every 10-degree rise or fall in temperature. The institute says that nitrogen has a more stable pressure since it has larger molecules than oxygen that are less likely to seep through the permeable tire walls.

3) When air is pressurized, the humidity in it condenses to a liquid and collects in the air storage tank you use at the local gas station. When you add compressed air to the tire, the water comes along for the ride. As the tire heats up during driving, that water changes to a gas, which then expands, increasing tire pressure. Because nitrogen is dry, there is no water in the tire to contribute to pressure fluctuations.

WATER (Ballasting of the tire): 

In certain cases, to increase the adherence weight or lower the machine’s centre of gravity, with Tubeless tires and ones with a standard Inner Tube, weighing tires with a liquid is one solution.

Agricultural tire valves are of the “air and water type”.  Therefore, filling up to a maximum of 75 % maximum (diagram 1), with liquid (water + antifreeze) is possible (volume indicated on the product data sheet size page).
In winter, as temperatures may fall below zero, a Glycol-based antifreeze product should be used.
With the valve at the top, fill the inner tube or Tubeless tire up to the height of the valve, at the same time allowing the air to escape (Diagram 2).

Inflation and pressure are adjusted to the air.

Since the volume of air responsible for pressure is low (around 25% of the volume), regular monitoring of the pressure is essential. We recommend verification on a monthly basis.

Ballasting of Tubeless tires with liquid

1. Fit and position the tire, see hypertext link to “Inflation and positioning of beads”
2. Deflate the tire to a low level of pressure (around 7psi 0.5 bars)
3. Position the valve at the top
4. Ballast the tire with liquid (water + antifreeze) up to a maximum of 75%, allowing the air to
   escape (Diagram 2),
5. Finish inflation with air and adjust the pressure

REFERENCES

1. http://agricultural.michelinman.com/us/Properly-use-your-tires/Ballasting-tyres-for-better-use
2. https://www.quora.com/Can-you-mix-nitrogen-and-air-in-tires
3. http://www.popularmechanics.com/cars/how-to/a3894/4302788/
4. https://www.tirebuyer.com/education/nitrogen-vs-air