[Vehicles] Gunpowder Engines and Stirling Engines

[Anthony]

Originally Posted by Varyon

A quick look online indicates some modern smokeless powders have energy densities a bit north of what gasoline does, if you need to bring oxidizer with you for the gasoline (gunpowders typically contain their own oxidizer).

I suspect that depends on what you're using as an oxidizer. I can't find any evidence for smokeless powders (or, really, any conventional explosives at all) that beat the energy density of LOx/gasoline (it's significantly higher than octanitrocubane)