Fuel is a type of ammunition found in Chapter 6 of Metro 2033 Redux, in the Metro Last Light DLC, Developer Pack, in the Spider Lair mission and the Developer Pack level, and also in the first Metro Exodus DLC, The Two Colonels. It is used only by the Flamethrower. Before Metro Redux came out, fuel was not considered as ammunition and player had infinite when available (such as when using the mounted flamethrower in the Dark Star mission).
Though the type of fuel is not specified, it appears to be a gaseous fuel, most likely propane - flamethrowers normally use a liquid fuel and do not actually throw flames, but coat the target in burning liquid; the Metro flamethrower is an exception in that it actually does throw fire, hence its very short range. The gas is stored in a tank on the users back and connected to the flamethrower with a hose, where it is ignited with a spark device.
In Metro Last Light and Metro Redux, fuel can be found in three different containers - a red pressurized tank which gives 10 units of fuel when picked up (on Normal difficulty), an angular plastic liquid container and a jerry can (both usually give 3-5 units of fuel when picked up). It should be noted that fuel containers explode when they catch on fire and can't be picked up afterwards, so caution must be used when using the flamethrower or explosives in areas with pickable fuel containers.
In Metro Exodus, fuel is only encountered in The Two Colonels DLC and Khlebnikov can pick it up on numerous occasions and use it with his flamethrower. This time, fuel containers always look like a small red jerry can, similar to the largest magazine that can be mounted to the Flamethrower. Picking up one can can give the player anywhere from 10 (or less) to 200 units of fuel, most often between 50-150 units. However, the flamethrower consumes fuel at a much faster rate than it did in Metro Last Light. Fuel can also be crafted at a workbench, crafting 45 units of fuel costs 10 Chemicals.
- The fuel is used by enemy in another way, the gasoline cans are used by the enemy as wired trap.
- Aside from finding uses in weaponry, the people of the metro value fuel extremely high considering it can be used to power generators which in turn provide the metro with electricity. Fuel also is used to power motor Vehicles which gives it high barter rates among travelers who can afford such luxury.