The 1958 DKW 3=6 looked like a modest family saloon, but its engineering was a quiet rebellion against four-stroke orthodoxy.

Name a type of terrain, and someone, somewhere, will figure out a way to race on it. From wood-track ovals and countryside rallies to the pure chaos of the Gumball 3000, humans love to pit themselves ...

Unless you're really into dirt bikes, you probably haven't touched a two-stroke engine in decades — if you ever have. These mechanically simple motors combine the four strokes we all know and love ...