Two things I'd like to add from my own personal experience:
1) I recently took a "trip" to test the Model S range and get a feel for driving long distances in an EV. Because I was driving in an area with lots of level 2 stations and fully expected I would make the trip with no problem, I only charged in standard mode. I left with 238 indicated miles, drove 103 miles, stopped for lunch for 50 minutes (approx. 15 miles of charge accumulated), then drove 103 miles back (I had some errands to run on the way home, so my return milage was actually a bit higher, but I forgot to note the actual milage traveled). At any rate, I drove around 206 (probably closer to 210) miles with no issue driving between 65 and 75 mph (as speed limits and traffic allowed), in temperatures varying between 42 deg F and 50 deg F. I drove comfortably in the cabin, as I would with an ICE (well, not quite. I find the seat heaters in the Tesla more effective than anything I've ever used, so I tend to only use those...but I had to use the defroster a couple of times). I arrived home with 14 miles rated range left (strangely enough, when I got off the freeway I actually had 34 miles left...after stopping for my errand, I returned to the car with 22 miles left. I lost 12 miles rated range as the battery cooled sitting in the parking lot, so my continual driving range would have probably been slightly different). The moral of the story is that I found the rated range to be within 10% of the EPA rated range (which is on par with my Prius (EPA estimated 51 mpg in the city...I've been getting more like 46 in our recent cold weather...).
2) Perhaps more importantly, because Model S is an electric vehicle, the immediate focus becomes the range. "How far does it go?" is the most common question I receive when people find out the Model S is electric. I've never once been asked that by someone regarding my gas car. People will ask "What kind of gas mileage do you get?", but never do I get "How far can you go?". It just isn't how we've learned to ask questions about cars. 50 MPG means something to people. 300 Wh/mi means nothing to most people (myself included until I started driving the car), so, instead, car manufacturers have to put a mileage number on the range of the car. With gas cars, people drive at high speeds on the freeway and don't think about the impact it has on the range of their vehicle because of the abundance of gas stations. While there are far more plugs than gas stations, not all plugs are available for charging the car, so a little crafting is necessary with EV driving (at least, until the supercharger network is built out). My Model S replaced my Lexus RX450h. I regularly got 400 miles on a tank of gas in that car with my average daily driving. However, on a recent road trip I took in that car, it was full of stuff, I had a car topper on it, and I was driving at a rather healthy speed :wink:. I was able to get about 270 miles on a tank, at best. My fuel economy went from my usual 26-28 mpg to a nasty 19-21. I didn't find myself faulting Lexus for faulty advertisements or lofty goals. I recognized that my fuel economy was suffering and, in order to recover it I could a) slow down, b) unload some stuff, or c) remove the car topper. Since none of those options were things I wanted to do, I elected to pay more money in gas for the trip. Instead of making the trip in 4 gas stops like I had planned...I had to make 7 or 8. So my choices for driving the car made the price of my trip go from about $200 in gas to $400. The same idea applies to Model S. If you aren't achieving the fuel economy you want, you have to modify the way you are driving or charge more often.
As long as I can remember, the 300 mile range always came with the 55 mph disclaimer. To me, that says for real driving, I'm going to get less. Same with EPA numbers. I shoot to achieve them when I drive, but I'm not surprised if I don't. I do find it unfortunate that this information isn't slightly more publicly available from Tesla (thanks to ChadS for what he has put together on this forum), but at the same time, it isn't all that different than ICE vehicles. Whether fueled by oil or electrons, you only have a certain number of Joules worth of energy in your "tank." Your burn rate will let you know how far you can go (MPG or Wh/mi). It's a matter of all of us newbie EV drivers getting accustomed to a new unit system and how to plan based of the information the car is giving us.
. I also wanted to drive to places nearby as we sight see, maybe 50 miles of driving.
