The current Model S is actually on par with the model 3 in terms of battery and drivetrain. They continuously update it. They stuck the Model 3 motor type into

The current Model S is actually on par with the model 3 in terms of battery and drivetrain. They continuously update it. They stuck the Model 3 motor type into the front of the Model S and primarily uses that for driving. You get to use the less efficient induction motor in the back for high accelerations. The chemistry in the battery is also the same but in a slightly different format. I have a Model X and it's also updated in this fashion. They have come a long way since the 2012 Model S. I suspect they will come out with a 100 kWh Model 3/Y though and it seems that the efficiency/range should be compared to these as you say instead of the big cars.