Over the winter the efficiency of the Model 3 was nothing to write home about. The resistance heater while effective uses a lot of electricity. Now the weather has warmed up the more efficient air conditioner is being used and the efficiency of the Model 3 is way better than I ever got from our LEAF.
The best summer efficiency in the LEAF I achieved was about 4.5 miles/kWh or 222 Wh/mile. By comparison today the Model 3 achieved 5.8 miles/kWh or 173 Wh/mile. What makes this more remarkable is that I drive the Model 3 about 5-10 miles per hour faster than the LEAF, speed reduces efficiency. The Model 3 is rated for 245 Wh/Mile so I should be able to exceed the rated range of 310 miles per charge by a wide margin, it works out to be about 440 miles.
The cars lifetime efficiency is 281 Wh/mile or 3.6 miles/kWh. I think this will improve as the year goes on. I imagine efficiency will drop slightly in mid summer as the amount of air conditioning required will increase.