think of an engine as a giant air pump. It gobbles up air from the atmosphere and dumps it into six cylinders. Inside each cylinder, the air is mixed with fuel that is sprayed in by the fuel injectors. The spark plug ignites, causing a small but powerful explosion. This explosion rapidly expands the air that is inside the cylinder, forcing the piston upwards. The piston is connected to the connecting rod which turns the crankshaft. The crankshaft spins and is connected to the transmission, driveshaft, rear differential, and finally, the rear axle and wheels.