For payback you have to do your own math based on mileage driven, your cost of Electricity and your cost of gas and your mpg on your ICE car.
Here's how I would figure mine
Miles driven / year = 12000
the EV gets about 4 mile per kWh so kWh = 12000/4 = 3000kWhr
Where I live Electricity costs about $0.11 per kWhr so
Fuel Cost for EV is 3000 x .11 = $330 per year
I have a 2012 Focus ICE that gets about 30 mpg doing the same kind of driving
so 12000 / 30 = 400 gallons of gas
at 4.00 per gallon gase cost would be $1600 per year
so fuel savings with EV is 1600 -330 = $1270 per year.
The EV has about every bell and whistle known to Ford so you really need to compare to a titanium at about $26000
My EV dealer price was a little over $37000 with the federal tax credit (7500) cost is $30,000, 4000 more than the ICE version
So based on fuel alone the payback would 4000/1270 = 3.2 years and that is without taking into account maintenance savings i.e. no oil change, brakes last forever, many fewer moving parts to wear out etc.
Not factored into the above is the pure fun of driving the car