In my opinion, the most important invention is the crankshaft, which was invented in 1876 by Karl Benz and Daimler Gottlieb. This invention revolutionized the world of motors because it changed the shape of its mechanism. As a result more efficient vehicles were created and the most important thing was allowed to transform the rectilinear movement of the piston into circular movement. I think, the counterweight system is incredible so that it works correctly and makes the engine times complete, to this day every combustion engine uses a crankshaft and is in charge of transmitting the force and power that generates the explosion to the wheels of the vehicles, life without them would be another and we do not take for granted that it is present when we start an engine.