No, you don’t. And the alternative implementation is that you either go through all code where car is used and add conditionals for all the cases where kind of fuel matters. Or is very common for this kind of programming, just copy the whole car.roadTrip() where fuel is called and to the method electricCar.roadTrip and just change a few lines. Then of course all requirement changes or bug fixes must be done in several places thereafter.

My feelings about people that can’t handle abstractions is that they just don’t have had to create or maintain anything complex. Very few real world systems can be kept in ones mind in full.