Fuel is a resource needed for the operation of vehicles with combustion engines, including trucks, tanks, aircraft, and ships.
Fuel is primarily refined from oil. Each unit of oil produces 48 units of fuel per day. The effectiveness of this refining process can be significantly increased by researching fuel refining technologies. The economy laws below war economy reduce the effectiveness.
Synthetic refinery buildings provide an additional source of fuel without requiring oil. They provide 48 units of fuel daily as a baseline (equivalent to one unit of oil) but this can be massively increased, with fuel and oil refining technologies (up to +250%). Their production is not negatively affected by economy laws.
Finally each country has a small base production of fuel, 48 units per day.
In contrast to strategic resources, fuel can be stockpiled. This allows countries to run a deficit in fuel for some time without immediately incurring penalties to its forces. As a baseline, each country can store 50,000 units of fuel plus 750 for every level of infrastructure in any of its states. Building fuel silos increases this capacity by 100,000 each, but they are vulnerable to bombardment and capture. Economy laws reduce the storage capacity to varying degrees.
When capitulating a country, 50% of its fuel stockpile gets captured, 25% when annexing it.
Depending on their mode of operation, units consume fuel proportional to their nominal fuel consumption as shown in the unit details. If they run out of fuel, they suffer severe penalties to their movement and combat abilities.
Divisions need fuel if any of their combat battalions contain equipment that consumes fuel, such as trucks, half-tracks, tanks and self-propelled guns. These divisions are marked by oil barrels next to their name in the unit selection panel. The effective fuel use per day is 12 times the fuel usage shown in the division's stats. No fuel is consumed while standing idle and during strategic redeploys and naval transfers. It is doubled when fighting while moving at the same time.
Each division has an internal storage lasting for 4 days of continued use. As long as the country has fuel available, they can refill via the supply system, at twice the normal consumption speed. If their supply zone is overloaded, the fuel flow is reduced and eventually stops at 50% overload. For example a supply zone providing 20 supply containing units requiring 30 supply will deliver no fuel at all to those units as other supplies take priority. When divisions fall below 25% of their internal fuel storage, they start to suffer increasing penalties, finally getting reduced to 40% movement speed and 10% battalion combat stats when no fuel is left. Training divisions earn no experience after running out of fuel.
All aircraft use fuel while on missions (except rocket interceptors which don't run on oil-based fuel). The effective fuel use per day and aircraft is 8.4 times the nominal fuel usage shown in the wing's details. When only operating at day or night, the fuel consumption is reduced accordingly.
Some mission types have non-standard fuel consumption:
- interception mission: 20%
- Kamikaze: 75%
- port strike: 120%
- training: 80%
When running out of fuel, air missions receive a 75% mission efficiency penalty.
The effective fuel use per day is 2.4 times the nominal fuel usage shown in the ship's stats. Ships have particularly high fuel consumption, so their mission assignments need to be carefully considered. Ships consume twice as much fuel while in combat but otherwise don't consume fuel when staying in position (whether in port or at sea). This includes task forces on naval invasion support and strike force missions while they have nothing to do. The training mission only uses 80% fuel.
When ships run out of fuel they receive penalties of up to 75% to speed and range and 50% attack.