@TexugoMaldito
Basically, any non-combustible fluid aids when it comes to drilling. It's not necessarily about making the drill faster and harder, it's about keeping the metal tip of the drill cooled down. There's a lot of physical energy built up from the rotations of any drill, which causes them to overheat very quickly, especially if your diving into something like similar metal. Even if you use a regular hand drill you could buy at Wal-Mart, after using it for a few minutes, you can touch the drill bit it comes with and it will be scalding hot.
A large industrial drill would likely be designed in some way to have a built in temperature system, to tell the drill itself to stop when it's about to overheat (the Burner Drill would have something like a thermometer wired to a basic forced shutoff switch). A heated drill bit burns out quickly, dulling itself, therefore becoming costly and time consuming to constantly replace. That's why in-game, you'll see the drills diving into the ground for a bit, then raising up to take a break. Specialized lubricants are the best for absorbing the heat produced by the drills and slicking them up, but water could be used as well, although it's nowhere near as effective, hence the respective 25% and 75% being pretty appropriate.
Also, at the factory I used to work at, my boss used a special mixture that was diluted in water to make this kind of turquoise colored lubricant, so water is pretty important in general. So there's your drill fact for the day.
