Fuel

The default capacity is 80,000,000 KG.

You can increase the capacity but you will be removed from realism mode, and it is not possible to get back to realism mode without a restart.

There are a button at top right corner where you can purchase 100,000 KG instead of typing.

When viewing ingame Fuel page, you may see the info: The fuel data consists of:
 * Chart of Fuel Price
 * Tank status
 * Fuel data
 * Fuel price adjustment
 * Capacity limit
 * Capacity available
 * Holding
 * Total cost

When to buy fuel?

 * When the price is at the lower such as $200.

How much fuel to store in tank?

 * Store as much as you can. Preferably the maximum amount.

Does fuel consumption matter?

 * Yes. Lower fuel consumption is always better but then there is also other factors like, range, pax and cost of an aircraft. See my hanger section for more information.