Mike’s post about ethanol and fuel economy raises an important general point: fuels and the technologies for burning them are strong complements. Engines are not one-size-fits-all fits with different fuels, but are highly customized.
We see this in history, too. The move from the use of whale oil for lighting to kerosene for lighting was something that consumers valued, because whale oil was smelly and smoky and was increasingly expensive; kerosene gave a cleaner, brighter light and was cheaper. But whale oil lamps couldn’t be retrofit to burn kerosene, so until someone cracked that technology nut, kerosene lighting did not disseminate widely.
If you are interested in such history, I recommend Daniel Yergin’s The Prize; the first couple of chapters cover the episode I just described. We’ll also be discussing that in a couple of weeks in my freshman seminar.