This episode originally aired May 8, 2011.

Correspondent Dan Goldstein starts off this week with a look at advanced engine technology. For more than 100 years, automobiles have relied on the internal combustion engine, despite its inefficiencies and limitations. But a new generation of engineers is working on a better engine, one that runs more efficiently and gets better gas mileage. In "Not Your Grandpa's Engine," Dan looks sat some of the new designs being pitched to auto makers and finds out how they're being received in Detroit.

Next, on "Energy Then" -- one of the predecessors to today's electric vehicles was the Both Electric, produced in Australia in 1940. This spunky three-wheeler was used mainly for deliveries and essential transport. But it was touted as an urban transportation solution that was easy to drive and parallel park.

On "The Mix," anchor Thalia Assuras talks with Jeremy Anwyl , CEO of car rating website Edmunds.com and Mary Beth Stanek, Director of Environment and Energy at General Motors. They discuss whether electric plug-in and alternative fuel vehicles could replace internal combustion-based cars and trucks.

Next up, electric cars hit showrooms this year, but they're not new. Just ask the thousands of drivers who have converted their internal combustion vehicles to run on electricity. In "Electric Car Conversions," Lee Patrick Sullivan meets the people who make it possible and one of their happy customers.

Finally, in this week's "Hot Zone," the first ever trans-atlantic biofuel flight. A plane flew from Morristown, New Jersey to Paris, under the power of Honeywell's "green jet fuel." The mixture is made from conventional oil, as well as a derivative of camelina - an inedible plant with high oil content that's cultivated in Montana. The fuel is awaiting FAA approval before it can be sold commercially.