Let me try to pare it down a little, and this example still makes electrics look good.
Tesla lists itself as
135MPGe, which is inconceivable in a gas car with those performance figures. "Obviously" something has gone horribly wrong here in the comparison of electricity to gasoline, can we agree on that?
Now figuring out the exact numbers to use is a laborious process. But if we borrow the well(plant?) to "pump" efficiency numbers from the
Department of Energy, %30 electric/%83 petrol, we get an adjusted mpg of 48MPG.
This still makes the tesla something to drool over, and 48MPG is certainly a lot more believable equivalence number than 135MPGe.
Does that reasoning make sense?
Note, I'm not promoting petrol, just trying to establish a fair basis for comparing the alternatives.