Machine Fuel

Drill Fuel is a statistic that is needed to use Drills. Different types of fuel can be applied to a Drill in a Drill Anvil. The most efficient type of fuel used to be Goblin Eggs, which are still relatively easy to find and grants Drill Fuel. However, ever since the 0.12 crystal hollows update, Oil Barrels is much more efficient if you are not buying in huge amounts as Goblin Egg prices are much cheaper when bought in large amounts. But if you have an infused Fuel Tank, then Oil Barrel might be cheaper as Oil Barrel gives 5x as much fuel and 5 goblin eggs, even when purchased in big amounts, would cost much more than barrels. However, when bought in singles, Oil Barrels is around the same price as Goblin Eggs but gives +10,000 Drill Fuel. It might be because that they can't be used on anything except for drill fuel but Goblin Eggs can be used on many things such as Goblin Omelette.

Fuels
Applying the below fuels to a Drill at a Drill Anvil will refuel the drill. Apart from the Flower types, the other fuel sources are only obtainable in the Dwarven Mines or Crystal Hollows. Goblin Eggs can be obtained as a rare drop from any type of Goblin apart from the Golden Goblin and Raid Goblins. Volta can be obtained as a rare drop from Ghosts. Biofuel can be purchased from Bubu or obtained from the Jotraeline Greatforge located in the Forge Basin. Goblin Eggs are the recommended fuel source for Drills if you don't have a infused fuel tank and you have over 1,000 Drill Fuel, due to the fact that they are easy to obtain and provide large amounts of fuel.