Yes, in the very early days the initial rating was 300 (ideal) miles. Then the Model S was rated by the EPA at 265 and that became the default number Tesla used on their site and in promotional materials. Note that on the RWD 85s, 300 ideal miles still equals 265 rated miles and you can toggle between these displays using a setting on the center panel. Other battery sizes have less, and the AWD versions have different ideal/rated ratios.