Abstract: A device for vaporizing the gasoline droplets in air-fuel mixtures from conventional carburetors to improve fuel combustion in internal combustion engines. The device has a relatively thin, box-shaped body enclosing flat upper and lower chambers separated by a thin aluminum partition, the chambers being of equal size and shape. The body has an opening in its top into the upper chamber, offset from the longitudinal center of the chamber, and an aligned opening in its bottom, and is designed for installation between the carburetor and intake manifold of an internal combustion engine. The thin aluminum partition has two transverse slots, one offset in one longitudinal direction and the other offset in the other longitudinal direction from the aligned openings in the body of the device. When the device is in use, air-fuel mixtures from the carburetor pass into the upper chamber from the opening in its top, where they are deflected in the direction of one or both of the transverse slots.