>>You have to look at total energy consumed to get a meaningful figure
But that is not the measurement. MPG means Miles Per Gallon. How far you have gone divided by how much liquid fuel consumed. They did invent MPGe (MPG equivalent) but that makes no sense. How many "gallons" of electricity are in your batteries?
Wh/Mi, Watt Hours Per Mile.
A gallon of E0 gas has 34.02 kWh, B0 diesel has 37.95. Obviously Ethanol and Biodiesel mixes will modify those numbers. That is the best way to get total energy consumed.
According to the math, my last tank of gas gave me:
23.02 mpg (US)
27.65 mpg (Imp)
10.22 L/100 km
4.34 gal (US)/100 mi
Whatever Wh/mile electrics and/or hybrids use when they do their math, taking into account their plug-in recharge, can be compared to my 1463.73 Wh/mi
Leaf owners are starting to put that on their cars.
The Ampera/Volt is the best of both worlds as you can run on battery for literally tens of thousands of miles w/o using gas. That link I posted, that car only used gas for 1.15 miles out of 10,053.27 miles.
When I get a hybrid, it will be a Volt (or another serial-hybrid).
Im still sceptical about hybrids and electric cars. Some you have lease the battery at around $15 a week. Other you dont, but have to replace the battery every few years at a cost of $18,000!
Much better off driving a small diesel that does almost 100 MPG and a bit of clever hypermiling. I dont do that many miles these days, probably less than 10,000 a year, so even though I only get 35 MPG and fuel is $8+ a gallon, I still dont spend much on fuel.