Certain parts of a car’s engine can reach temperatures in excess of 1,500°F. With this in mind, the engineers at BMW developed a way to boost efficiency: Transform that otherwise wasted heat into energy the engine can use. The resulting Turbo- steamer reclaims more than 80 percent of the heat lost from the engine’s exhaust and cooling systems. It uses this surplus heat to generate steam that helps drive the engine. It boosts power and torque by 10 percent and cuts fuel consumption by 15 percent without using a single additional drop of gasoline.