I believe i figured out how to convert your mpg to wh/mi in the aerodynamics tool!!!!!
Plug in all your numbers. Then take the watts (hp conversion) and divide by the mph in the same row.
(Again, these are projections for your car)
for one hour at 65mph, 3821watts / 65miles = 60.78wh/mi
(on the conservative side i'd think it would be higher in the real world.)
But this also tells us that to make your car a serial hybrid with an infinite range on gasoline. You'd need at minimum a 3.82 kwh generator. Say 4.5-5kw generator to be safe and account for losses.
This gives you an idea of you would need. It would basically be plug and play for a 120volt battery pack. Like carrying an electrical outlet with you everywhere you go!
http://www.electricgeneratorsdirect....tor/p6398.html
$1,859
389cc
Weight: 177 Lbs. (80.29 kilograms)
Dimensions: 26.8L x 22.8W x 22.6H
(68.07 x 57.91 x 57.40 cm)
6 gallons fuel tank.
So $4,050 80 miles battery pack + $1,859 generator = $5,909 for your gas "tank." 327lbs combined. But since it's portable, you can save 177lbs of weight and increase your cargo area when you don't need it.
It would get you the electric range of a Nissan Leaf, with the extended range of a Volt, at Prius mpg.