Now, now, there is no need for insults. Let us give him the benefit of the doubt. Yes, the chemical energy contained in gallon of gasoline is 33.6 kWh, but there is no engine in existence capable of using 100% of that chemical energy. (As I am certain you know, the total energy available in a gallon of gas is probably much higher, E=mc2 and all.) How about we amend the comment to "The amount of energy extracted from a gallon of gas entirely depends on the efficiency of the engine burning it." I think that is much more constructive.
If an EV-1 uses 33.6 kWh of energy, that is equivalent to an internal combustion engine using 100% of the chemical energy in a gallon of gas in the same instance.