Dieselpunk or Decopunk?

I am a newcomer to the Dieselpunk world. I’ll admit that right up front. Many have paved the way before me. In order to understand the genre, I’ve read the fiction and I’ve read the discussions and attempted definitions.

From my reading, I gather there is no hard set definition as of yet. There is, however, a certain understanding of what is in-bounds and out-of-bounds. Having gotten that far, I was then thrown for a loop when I discovered the term “Decopunk” and even more puzzled when I learned “Decopunk” occupies the same time period as Dieselpunk. So what differentiates a story as Decopunk or Dieselpunk? Is it a simple case of authorial whim?

It seems the granddaddy of all the punk genres is cyberpunk. So what is cyberpunk? As near as I can tell, cyberpunk is set in the future, on earth, features advanced and invasive computerized information technology, and is dystopic. It has noir and hardboiled elements and is often nihilistic.

Writers, always looking for new turf to plow, began applying the punk characteristics of individualism and anti-establishmentarianism to the Victorian Era. An appropriate field to plow due to the rapid technological advances of the era, their vision of a high tech future, and the dark undercurrent which existed beneath the prim and proper and polite surface.

Steampunk, however, to my mind, seems to focus more on alternative history and the generally progressive mood of the Victorian Era. It does not seem to be overly dystopic in tone.

Dieselpunk is definitely grittier; incorporating to a greater degree the noir, hardboiled, and nihilistic elements of cyberpunk. There may be an optimistic note, but war and totalitarianism always seem to be lurking in the background.

So where does Decopunk fit in? How does it differ from Dieselpunk? Supposedly, Decopunk is sleeker and shinier that Dieselpunk. It is the chrome-plated version. It is the car, without the grease and oil covered mechanic nearby. Decopunk seems more focused on the art of the era: Art Deco and Streamline Moderne. Somewhat less of a technological emphasis in favor of an artistic one. Art rather than diesel. It might be a bit more positive as well, reflective of the art of the era.

As always, I look forward to your comments and opinions!