Speaking of full electric tanks, I checked the "mileage" of my Zero today. I was able to travel 75 miles and it took 8.7 kWh @ 26 cents a kWh to go that distance, costing $2.26. The same ride on one of my motorcycles that get 50 mpg @ $4.04 per gallon for regular fuel would cost $6.06. Your results may differ, especially if you don't live near San Francisco and ride a 70 mpg Royal Enfield.