The Tesla is strange because that number on the dash is "rated miles", or the best you're going to get. So you can't just drive to empty and get a number you can compare with others, unless you drive it in quite a certain way.

My S60 says something like 215 miles when fully charged, but when driving on the Interstate the actual range is more like 160 miles, with the cabin heater on. It can vary significantly due to rain as well, a recent trip that had a leg almost entirely in very heavy rain caused a significant drop in range.