The Wave engine has been posted about before, but I still find it an intriguing idea, especially for something like the Volt that uses gasoline only as a generator, so it's able to run at an optimal efficiency. This type of engine is, seemly, perfect for that kind of application.<p>I find it interesting that this modern engine is actually significantly less complicated than the 100-year-old engine it's replacing. It seems that technology is often about refining ideas to their simplest form rather than getting more complex (e.g., the Atom is a much simpler CPU than standard x86 processors)<p>It looks like it's going to be several years before it's commercially viable.