EcoMotors OPOC internal combustion engine is an update of two-stroke powerplants. The acronym stands for opposed piston opposed cylinder, which describes a "module" consisting of a pair of pistons moving in each of two horizontally opposed cylinders. Simply put, when the twin pistons start a compression cycle (move toward each other) fuel is injected for combustion.

The company claims production cost is 20% less than conventional engines thanks to half the parts. The engine also uses an electric turbocharger. Ganging modules together and using an electric clutch to shut down one module when its power isn’t needed yields a 45% gain in efficiency. And a hybrid arrangement of two power modules and electric motor/generator would boost efficiency another 10%, say EcoMotors. (Ed. Note: That last number seems low to me.)