I drove from Savannah GA to Florence SC on Sunday, a distance of 180 miles. I charged to 240 miles, figuring that is a 60 mile buffer, of which I would use up 30 miles driving the 70 mph speed limit. Unfortunately, it was 40 degrees, raining and windy, and I arrived at the hotel with only 4 miles range left (I drove the entire trip with the HVAC off and range mode on). The last 45 miles I drove at 55 mph because I was concerned I would not get to my destination. I called Tesla to ask them how much further I could drive when it says 0 miles left, and was told 1 mile, maybe 2 or 3 if I am lucky. According to them, 0 miles left really means zero, not like an ICE, where empty means there are 2 gallons left. BTW, I have a P85, and they told me the Michelin Pilot tires I have reduce my range by about 20 miles.