I was wondering if butanol is a more efficient fuel than ethanol and, if so, why don't we hear more about it? -- Robert M., Kansas City, MO

There has been little to no effort to promote butanol as an alternate fuel because of historically low yields and low concentrations of butanol compared to those of ethanol; that is, for each bushel of corn you would garner (1.3) gallons of butanol (0.7) gallons of acetone and (0.13) gallons of ethanol with concentrations of 1-2%.