I think it's closer to 50% of the advertised range. Speed decreases range dramatically with speed and don't forget the reserve. Most ICE drivers doing highway travel refill at about 1/4 tank. Let's call it 20%.....and that's 20% of the full tank 400 mile range....equals 80 miles reserve. Some (like me) may push it to 40 miles reserve...but not less than that. The big battery Tesla advertised range of 300 miles (at 55 mph) drops to about 200 miles at 75-80. Then reduce that with a 40-80 mile reserve. And that's not taking climate conditions to account...which will only further reduce the range.
I think Tesla's strategy of portraying their car as a trip car is just wrong. But, a vast amount of passenger car is urban/suburban local and commuter travel which is fine for the Tesla. That really is it's market. Add to that government financial incentives and, more importantly, unencumbered use of HOV lanes and the EV begins to make some sense for those that can afford the Tesla S. As Tesla moves down market ($40) and faces broader competition from other EV manufactures those HOV lanes will begin to fill up.
So many dumb comments on this board. Of course you use more energy to operate in the cold weather! Duh. My gas mileage has dropped 5-8 miles per gallon now thanks to the oil companies adding more alcohol for the winter air pollution season. But you moronic shorts think that doesn't happen and that gas mileage is constant for an internal combustion engine. Just dumb!
No more than 5% mpg loss due to ethanol (assumes 10% ethanol in the fuel). That's a fact. Problem is you are paying more per gallon due to the added expense of ethanol. So it's a double whammy...more $ per gallon and less MPG. Don't blame the oil companies, the Fed Gov mandated the use of ethanol in gasoline....in part due to emissions and more so due to renewable energy initiatives. So now we are burning our food (corn) in our cars and paying more for food in the grocery store. Corn prices have more than doubled due to the Gov mandated use of ethanol in gasoline. Why can't the Gov let free market forces prevail? Anyway....that's my story.
This is also confirmed by reading the posts of the actual owners on the Tesla forum and at TMC. So if you want to simulate owning a Model S take your ICE car for a ride on the freeway in below freezing weather and turn off the heat and do not exceed 55 MPH.