I didn't know what to put as a picture, so I just used a picture of a ship I made. (It uses this mod though)

This mod requires Interstellar Fuel Switch.

Fourian Fuel Systems overhauls the fuel in the game by replacing the generic LiquidFuel and Oxidizer to three different fuel types modeled after real world fuels

Kerbolene + Ozonate:

Kerbolene is based on Kerosene (hence the name Kerbolene) and Ozonate is based on Liquid Oxygen. (Fun fact: Ozone is a real world oxidizer that's stronger than O2) This fuel mixture is used mainly in lower stage engines for lifting heavy objects. Kerbolene is also used as jet fuel.

Finazine + Oxide:

Finazine is based on Aerozine 50 which is a mixture of Dimazine (AKA unsymmetrical dimethylhydrazine) and Hydrazine, and Oxide is based on dinitrogen tetroxide. This mixture is used in upper stages and in vacuum. It is also denser than Kerbolene + Ozonate, so tanks for it will be smaller.

Hydranepsin + Ozonate:

Hydranepsin is based on Liquid Hydrogen, which is a fuel used in the Space Shuttle and the upper stages of the Saturn V. It is less dense than the other fuels so the tanks for it will need to be pretty big.

Notes:

• The LV-N uses Hydranepsin.
• Non-supported mods will work, except all the engines will all use Kerbolene + Ozonate. The tanks will work as they should though.
• This is a WIP mod, I plan to add much more in the future.