Matt,
887 + 66% = 1472 < 4423 + 17% = 5174
or
887 + 66% = 1472 < 2250 + 17% = 2633
I very much doubt that it only takes 17% of a gallon of gasoline to produce that gallon of gasoline. The would be 33.4 x 17% = 5.7kWh. Nissan says it take 7.5kWh just to refine a gallon of gasoline, let alone all the rest. It might be as high as 10kWh/gallon, all told.
You have not convinced me, that 1472 is greater than 5174 or 2633.
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Doing this sort of math is fairly arbitrary and capricious though, I think. It is like saying that since only ~20 gallons of gasoline and 10 gallons of diesel come from 42 gallons of oil, we need to account for the other 12 gallons by adding 8 to the gasoline and 4 to the diesel... So, for every gallon of gasoline or diesel you burn, you really are burning 1.4 gallons... bogus math!
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The efficiency of the drive train is accounted for in the BTU/mile (or MPGe) number.
EV's are now approaching 80-85% here, while most ICE's are stuck below 20%. Now, you might say; wait Atkinson cycle engines (like in the Prius) are up to 38% efficient! But they can only run at peak efficiency a small part of the time, and by definition, and system that requires a transmission is going to be off peak much of the time. There are transmission losses, and a warm up period, and all that heat production means crappy end use efficiency!
And as I said, the BTU/mile or MPGe number accounts for the efficiency of the entire drivetrain as a system. End use efficiency is what it is all about! If you can only use ~15-20% of the energy you put into the car (on a good day), then that multiplies the inefficiencies of the upstream energy. EV's are so much more efficient in this stage -- look at the heat output!
MPGe tells the story in the vehicle -- X-Prize did this right.
Now, for the carbon footprint, sure you have to take full account of ALL the energy used along the way FOR ALL THE TYPES OF ENERGY, and no matter where it comes from. The electricity used to refine oil *may* come from the process itself, but if the generation of electricity is low efficiency for EV's, then it is the same for the embedded electricity used to refine gasoline -- for purposes of carbon footprint. Ditto for the natural gas used in refining. And for oil extraction, etc.
The
article I linked to in the "How much Energy does it take..." thread talks about 1.5% of all California's electricity is being used just for
extracting oil. Even if it is really >1%, then that is still enormous. Refining oil takes a lot more than that, plus natural gas, so if you use all that energy for running the EV's directly, then I am fairly certain that you come out
way ahead.