As you all know, most of the energy potential in fuel is lost through means of heat. Alot of this heat exits the engine through the exhaust gas. What if we could harness the heat in the exhaust gas to produce more power for the engine?
The heat in the exhaust gas heats up some through a heat exchanger fluid and this fluid becomes steam. This steam is used to power the engine. More than 80 percent of heat in the exhaust gases can be converted back into usable energy this way.
Click the diagrams on this page to show enlarged versions. The diagrams above show the exhaust gas path and the steam paths somewhat but in a test environment. We’ll look at more detailed diagrams of the parts involved below when equipped in a car.
This results in reducing fuel consumption by 15 percent, and an additional 14 horsepower and 15 lb-ft of torque for BMW’s inline-4 1.8 litre engine. And it doesn’t cost you anything as it is recycled from the exhaust gas heat.
Steam passes through an expansion unit connected to the crankshaft and that is what provides the car the additional power.
Currently it’s fitted on a 3-series with a 1.8 litre 4-cylinder engine as the 4-cylinder block leaves enough room in the engine bay for the additional components like the expansion unit to be installed. BMW is still working on designing the system to be small enough to fit onto any model.