Most EV’s should charge 40%-50% in 3 hours, on a level 2 charger. That should get you far more than 20 miles of range. More like 125-150 miles.

You’re still saving if you have to rely on superchargers. No vehicle maintenance as compared to gas too.

Gas Fuel: At $5/gallon assuming 30 mpg your cost per mile is $0.17

Superchargers at $0.50/kwh (will run a tesla for 4.56 miles): $0.11/mile

https://www.palmsevchargers.com/calculator/