The Department of Energy is funding research at GM and BMW, along with several partner universities, into a little-known technology called the thermoelectric generator. Internal combustion engines use a grand total of maybe 25-30% of the energy contained in gasoline for actual propulsion. Everything else is wasted running accessories, being consumed by friction and drag, or gets tossed into the wastebasket of exhaust heat loss. A thermoelectric generator takes advantage of the exhaust heat and uses it to make electricity — a delicious excited electron broth you can use for all kinds of recipes.

GM, BMW and its university partners aren't so much working on developing the technology as they are trying to shrink it — the original systems were developed 12 years ago by the government and tested on heavy diesel applications. They work by utilizing a dipole metallic medium which is heated on one side, exciting electrons which then flow to the cool side of the device. When the device is attached to an exhaust system, the energy created can reduce the drag on the alternator, allowing less engine drag and increasing fuel economy. The result on your average suburban goliath — 1 MPG. Neat-o kids! Hugely complicated technology with a result which can be bested by extra tire pressure and speed tape. [DetNews]