Technofile : Green engines

Engine oil made from rapeseed is a green alternative to petroleum-based oil,
according to Duane Johnson, a crop scientist at Colorado State University.
Johnson says the oil is just as good at lubricating, and is better for the
environment. Seeds ground up to release the oil can also be used as feed for
livestock. The oil reduces the amount of hydrocarbons burnt by a car—and
makes the exhaust smell of popcorn.