Greasy fast food may be bad for you, but it can be good for the
environment. Take cooking oil. A group of kids converted an old
school bus to use waste cooking oil as fuel. They drove it across
the country, stopping to fuel up at fast food restaurants. They’d
pull up to a restaurant, uncoil a hose, and pump the used grease
into the fuel tank. After filtering out the bits of meat, onion ring, or
doughnut, they’d drive away—fueled for free. Added bonus: the
exhaust smelled like Chinese food, fried chicken, or whatever else
got fried in the oil. And Mother Nature was happy—no harmful
soot or sulfur dioxide like with regular diesel fuel, and less used
cooking oil to clog landfills or pollute waterways. Grease-powered
buses motoring around at 60 miles per hour—no wonder they call
it fast food.