What Biofuel Is (And Where It Comes From)

Cars didn't always run on gasoline. Henry Ford envisioned his Model T's puttering along with tanks fully of ethanol. Early diesel engines ran on peanut oil. Of course, the discovery of massive petroleum reserves at the turn of the 20th century quickly put the brakes on that notion--why bother creating biofuel when gasoline and diesel are pennies on the gallon? But now that gas is about $3.64 a gallon in the US, interest in biofuels is on the rise. Here's what we'll use to power 21st century tran...