Comment by paxys

This is key, because not every mile driven is the same. If you see "Model Y has a range of 300 miles" and set out to drive 300 miles you are going to have a problem. The temperature, wind speed/direction, humidity, pressure, cloud cover, altitude, uphill/downhill driving, vehicle weight, battery quality, tire tread, AC use, average speed... all make a huge difference. The nav system does take these into account and gives you a much more realistic number.