My husband and I took a drive today to compare the energy usage of his P85 vs my 60. We took a 15.1 mile drive through mostly suburban streets, following the same route at the same speed - our own little Model S parade! The route was mostly reasonably flat except for the quite steep hill coming down from our house and coming back up the same hill at the end. We tried to control for all variables that we could (climate control off, windows closed, regen on, etc). My husband is about 60 pounds heavier than I am and he has the 21" wheels and I have the 19", so those were the main differences. In short, our results seem to validate differences in the EPA ranges. At the end of the 15.1 miles, total energy used for my 60 kWh S was 4.2 kWhs with an average of 276 watts per mile. Total energy used by the P85 kWh was 4.6 kWh and an average of 303 watts per mile. So the 65kWh car used only about 91% of the energy that the 85 kWh used to go the same distance at the same speed.