Spaceflight Simulator Wiki

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Fuel Tanks are fuselage sections that are located in the Basics, 6 Wide, 8 Wide, 10 Wide, and 12 Wide tabs in Build Editor. The are a huge variety of fuel tanks available in-game, weighing from 5 tons to 120 tons (at full fuel load). Most fuel tanks can only be accessed by the Parts Expansion, and more sizes of fuel tanks fuel tanks can be only accessed by BP editing. They contain liquid fuel and their amount can be adjusted. 90% of the Fuel Tank's mass is from liquid fuel if the tank is full.

Fuel tank sizes

In the game, there are fuel tanks that are available in any size. But in the building menu, only 5 sizes can be selected, ranging from 4 Wide tanks to 12 Wide tanks.

Mass of Fuel Tanks (t)
Sizes 2 tall 4 tall 6 tall 8 tall 16 tall Engine base
4 wide 5 10 15 20
6 wide 7.5 15 22.5 30 60 18.75
8 wide 10 20 30 40 80 25
10 wide 12.5 25 37.5 50 100 31.25
12 wide 15 30 45 60 120 37.5
Liquid fuel mass in Fuel Tanks (t)
Sizes 2 tall 4 tall 6 tall 8 tall 16 tall Engine base
4 wide 4.5 9 13.5 18
6 wide 6.75 13.5 18.75 20.25 54 16.88 (16.875)
8 wide 9 18 27 36 72 22.5
10 wide 11.25 22.5 33.75 45 90 28.13 (28.125)
12 wide 13.5 27 40.5 54 108 33.75


  1. Fuel for a rocket
  2. Space station modules
  3. Decorations
  4. Weights

Fuel tanks: Use in rockets

Fuel tanks are one of the most vital structures in a rocket. They have a storage container for liquid fuel and oxidiser. At the part where the fuel tank and engine connect, there is a series of complex structure which pump fuel to the engine and ignite it. As the engine continues to burn, fuel drains inside the containers. When fuel is gone, the engine shuts down, because there is no more fuel inside the tanks to keep it burning. The rocket stage then gets separated. The space shuttle's external fuel tank provided thrust for its main engines and has a container for liquid hydrogen and liquid oxygen.

Smaller Fuel Tanks are used in small rockets and/or upper stages. Larger Fuel Tanks are used in larger rockets and/or lower stages.


  • Prior to the debut of the skin change mechanic in 1.4, there were four types of fuel tanks of any size, two white and two orange.
  • The orange color in real life is the insulation foam sprayed on the tank to keep the cryogenic fuels cold.
  • If you have 2 parachutes attached to a fuel tank, one on top and the other on the bottom, they will adapt, then they would appear as a thin fuel tank, thinner than 2 wide, but thicker than 1 wide.
  • Most players simulate space stations with fuel tanks.
  • A player can make pressurized parts by adjusting the fuel amount to 0 tons.
  • Most fuel tanks are located on the lower stages of rockets, so that's why most fuel is spent on going to orbit.
  • In real life, fuel tanks only hold liquid fuel or liquid oxygen. The fuselage carrying those two tanks is called the tank section.
  • As fuel inside the tanks drain, the rocket becomes lighter, thus increasing the TWR of the rocket
  • You can make fuel tanks have more fuel inside, but that will make the rocket heavier.
  • You can also have negative fuel in your rocket, but a rocket with negative mass will fall down to the centre of the earth,
Basics ParachuteCapsuleHeat ShieldSeparatorFuel TanksHawk EngineValiant EngineKolibri EnginePeregrine EngineRCS ThrustersSide SeparatorSolid Rocket BoostersAerodynamic Nose ConeLanding Leg
6 Wide 6 Wide Aerodynamic Nose ConeFuel TanksSeparatorHeat ShieldEngine Base
8 Wide 8 Wide Aerodynamic Nose ConeFuel TanksSeparatorHeat ShieldEngine Base
10 Wide Fuel TanksSeparatorHeat ShieldEngine Base
12 Wide Fuel TanksSeparatorHeat ShieldEngine Base
Engines Titan EngineFrontier EngineHawk EnginePeregrine EngineValiant EngineKolibri EngineRCS ThrustersIon Engine
Aerodynamic Parts ParachuteSide ParachuteAerodynamic Nose ConeAerodynamic Fuselage
Fairings Fairing
Structural Structural Part
Other Docking PortLanding LegsIon EngineProbeRCS ThrustersWheelsSolar PanelFuel Pipe
Currently removed in Version 1.5
Removed in older versions
Probe (Large)Fairing AdapterAdapter