Stan I see your point however I think you missed mine so I too will try once more.

If it takes 1/4 gallon to go 10 miles using the ICE ONLY and this is due to it's inherit inefficiency I think that those same KW's are better put to use in powering an electric motor which even being charged by the ICE will go farther due to it's HIGHER efficiency.

As you pointed out all one can do to make gains in FE is to capture energy lost to inefficient technology. This is what the electric motor does in part. So what I said in my earlier posts holds up. Using better technologies to do the work yields better FE.