The engineering back 'n forth above, has been interesting....albeit of somewhat limited use. As I hinted way up towards the top, the science of say.....thermodynamics, is but one small piece of this overall puzzle. The serious practitioner of the science of thermodynamics, understands this. The amateur "scientist" and/or huckster, does not.
Here are just four (out of hundreds, if not thousands) of questions we need to ask ourselves, that an applied scientist may not consider in the course of his narrow focus, OR may not even occur to him:
-IF a pure gas car is more efficient (on engineering paper) than a hybrid, but due to its better mpg, the consumer prefers the hybrid, what difference does it make that the former is "technically" more efficient? (This question wraps the sciences of economics, marketing, et al, into the engineering equation).
-When we compare the thermal/energy efficiency of a pure gas car with a pure electric car, how does the practitioner of this applied science, account for the costs implicit in our accessing and preserving access to, foreign oil? Of course he doesn't account for these, as they're decidely outside his baliwick. He shouldn't be considering these costs in HIS equation. But, the rest of us are obligated to consider them in ours. (This question might touch on the sciences of politics, foreign policy, economics, and so forth).
-When comparing "losses" from an energy/thermodynamics standpoint - between say, petro and electricity, how can the applied scientist possibly account for all the various losses/costs, from the various energy's sources, to the point at which the rubber hits the road? The answer to that question is.....he can't, and the serious scientist knows this. Answering THIS question, would require the input of a whole host of different scientists and sciences.
-Also, when comparing "losses" from an energy/thermodynamics standpoint, how does the applied scientists account for the costs of these losses? For instance, the applied scientist may compare the energy lost out a gas engine's tailpipe with the energy lost by dint of delivering electricity by means of electrical lines. He can arrive at a formula suggesting that fewer "energy units" are "wasted" in the former instance than the latter. What he CAN'T do though, is assign a cost to those losses. For instance, is a "unit of energy" lost from an electrical line in the form of heat, equal to a unit lost from the tailpipe in the form of greenhouse gases? Of course it isn't. In order to put this question into context, we'd need help from say...environmental and climate scientists.