Joule

1 joule = 1 Nm = 1 kg m² s^-2 = 1 Ws

To get an impression of the joule, it is about the energy needed to shift a 100 gram (one newton) object one meter.
It takes 4186 Joules to heat a kilogram of water 1 degree Celsius.

1 kWh = 3.600.000 joule, or the amount of energy needed to heat 100 kilogram of water up 8.6 degrees Celsius.
the amount of energy needed to boil one liter of water from 20 to 100 degrees Celsius is 334.880 joule or about 0.1 kWh

If your cars weighs 1000 kilo, it takes 10.000 joules per meter to shift it, or 10.000.000 joules per km or 2.7 kWh per km, if there was no friction, like in space.