"Running LA - Tucson on
A Better Routeplanner shows about 1 hr & $15 of Supercharging to be necessary. In a gasser you might be able to drive that whole way without stopping, but why would you? Add a bathroom break, a refuel of the car and a meal on the road and I bet the time difference would be less than 15 minutes each way.
A return trip would use $30 of Supercharging on the Tesla. For the cost of gas to be only $12 more, that means you think you can do the round trip on $42 of gas. At an average of $3/gal (according to
GasBuddy) that means 14 gallons to drive 980 mi, or 70 mpg. What car are you planning on renting that gets 70 mpg?!"
I think there is some bad/inconsistent math in these two sentences. There is no way you can do 980 miles on only $30 of supercharging (in particular at $0.26 per KW in California). I don't think you included the cost of the initial charge which should be factored in for a fair comparision.
Also Tesla trips actually indicates that it's fuel saving is $12 each way which sounds more realistic and makes the math work out better.