Butanol can be blended with traditional unleaded gasoline just like ethanol, but it goes one step better than its ethanol cousin insofar as it can be combined with gasoline in larger concentrations than those of ethanol-gasoline blends. Butanol can also be blended with ethanol itself to reduce ethanol’s evaporation rate. In addition, E85 (15 percent unleaded gasoline and 85 percent ethanol by volume) requires upgrades to the fuel system due to the corrosive nature of ethanol. Butanol can be used undiluted as a vehicle fuel without changing the components of the gasoline vehicle.
Butanol yields an impressive 104,800 BTU/gallon far surpassing the meager 84,250 BTU/gallon of ethanol. Gasoline contains about 121,000 BTUs/gallon. This means the butanol in your Otto cycle internal combustion engine will yield fuel consumption close to that of gasoline. E85 increases fuel consumption by about 10 percent or more. The net energy released per air fuel ratio is higher for butanol than that of gasoline. Butanol burns as clean or cleaner than E85.
[Ed. note: BP and DuPont are currently working together on bringing biobutanol to market – you can read their press release here – it has alot of great information in it about the fuel, potential feedstocks etc.)