Tesla Road Trip Savings: My 27,615 mile (the circumference of the Earth is 24,901 miles) 48 State plus Canada road trip cost $8.37. I had to pay for electricity 2 times, the rest was FREE thanks to the Tesla SuperCharger network. There were about 180 SuperChargers when I started the trip. There are now almost 300 in the USA. Gas savings assuming a 25 MPG car using a national average of $2.75 a gallon = $3037.