Dieselpunk is an art style and subculture that blends the aesthetics / pop culture of the 1920s - 1950s with today. To dieselpunks, the "diesel era" was a time defined by warfare, Art Deco, pulp heroes, swing music, and noir gum shoes.
Me and John saw a group of cosplayers in a steampunk show that didn't look victorian at all. They wore fedoras, goggles, ww2 gear and retro-futurist tech, but from a different timeline. Turns out they were dieselpunks