My smart EVSE is claiming that my 21 mile round-trip daily commute is using 7 kWh/day...including pre-condition at both ends. Yes, that's about 3.0 miles/kWh, and the car's guess-o-meter is claiming 4.4 miles/kWh because it doesn't measure pre-condition power usage. At our local ~$0.15/kWh power cost, that is $1.05. My diesel pickup gets 21 MPG on the same commute, and you don't even need a calculator to see that it uses 1.0 gallons of diesel @ $3.10. My 4-cylinder race car hates that commute, and only gets 20 MPG on its required $3.75/gallon super unleaded.
My DW picked up a brand new Kia Niro 100% electric EV a few weeks after I bought my i3 last spring. She does a 90 mile round-trip commute, and the same smart EVSE is claiming that she is using ~24 kWh/day doing mostly interstate driving. She claims that her former 6-cylinder pickup was costing her $20/day in gas, and I calculate that the electric usage is $3.70/day.
Ironically, the business right next to the office building where my DW works just installed a free public L2 charging station on Monday. Depending on the guilt factor, her commuting energy costs might go down to ZERO! NY State is offering a $4,000/plug grant for employers to install charging stations for their employees. I am pushing the paperwork through where I work to install four, and trust me there will be zero guilt factor when my commuting energy costs are zero.
Back in the recent past, people used to get gas station credit cards where you had to pay the month's gas off at the end of every month. Charging at home and paying the power company is the same concept, only it costs way less.....