Biodiesel is a great idea (HCN, 8/8/05: The American dream, sans gasoline). But how long can we ferment potential food? Yeast exhales carbon dioxide, as do tractors, and those nasty artificial fertilizers are made from oil. Used cooking oil will not be readily available for long, as biodiesel fans burn it up.

Some long-term solutions may be as yet undreamed of, but bicycles and small cars come to mind. I bought a 1986 Chevrolet Sprint with 125,000 miles on it for $250 in 1999. It sports a one-liter, three-cylinder gasoline engine and an EPA mileage rating of 58 mpg. I have driven nearly 100,000 additional miles since then. No, I have never gotten 58 mpg; more like 53, but that sure beats all the hybrids and diesels. It still runs great, and it is not slow.

In 1989, Chevrolet changed the name to "Geo" and began selling a four-cylinder model as well. They dropped the line in 2000, just in time for the hybrids, costing twice as much, to hit the market. How timely.

No one seems to know about Sprints and Geos. Perhaps it is time to request the return of this great little car.

David Rigsby
Embudo, New Mexico