I probably misunderstood it :BangHead: I did not know lower octane fuels had more therms/unit. Diesel fans were very disappointed when oil refiners started charging for the extra therms the diesel contains. Even though it is one of the first products produced by the refining process, making it much cheaper to produce.
The lower the octane, the more power per unit volume of fuel. This is why you always want to run the lowest octane you can without knock to get the most power from your engine.