Can carbon subnitride be used as a fuel with similar properties to gasoline? I am trying to figure out if Dicyanoacetylene, aka carbon subnitride, aka $\ce{C4N2}$, can have a similar reaction with air as gasoline, or if it only creates a lot of heat but not much expansion?  As I understand it, the thing that makes gasoline useful is that when it combusts, the product has a much lower density than the reactants, causing a huge expansion to reduce pressure (which drives pistons in an engine).  Does $\ce{C4N2}$ have a similar effect, or does it have only comparatively negligible expansion compared to gasoline and simply generates more heat? Or might it produce a similar expansion or more than gasoline?
No
You wouldn't want to burn this thing anywhere, it burns like, 9010 degrees... Fahrenheit. It's nearly the temperature of the surface of the sun (around 900 degrees off). Not much can contain it. So unless you had some kind of super-metal, than you are out of luck trying to use it as fuel.