[NeilBlanchard]

Yes, virtually all Volt drivers are charging the battery daily, and so the ~8+ gallons of gas in the tank last for over 1,000 miles on average.

Of course the electricity costs something, and of course it should be counted in the overall MPGe. The EPA says the Combined mileage is 93MPGe, so I'm sure that by using a Volt with a large majority of the time in EV mode, that this will easily raise the overall efficiency.

What is the useable capacity on the Volt battery pack? Is it ~12kWh? If it drives 40 miles on that, and if you use the EPA's equivalency of 33.7kWh/gallon, then the Volt gets 112MPGe in EV mode. If you drive it 50 miles then it gets 140MPGe, and if you are a leadfoot or it is *really* cold and you only manage 30 miles, that equals 84MPGe.

If you drive 40 miles a day for 18 days, and then drive 350 mile on 1 day (40 miles on electricity and 310 on gas), you would use ~228kWh = 6.77 gallons + 8.5 gallons used for 310 miles (~36.5MPG in charging mode) that totals 15.27 gallons equivalent used to travel 1,070 miles = ~70MPGe overall.