[slg]

Have you reached out to Tesla service about this? The range being that far below what is advertised is not normal unless you are operating in some cold environments, you are blasting the AC, you are a maniac when accelerating, or you leave the car in sentry mode for extended periods of time. You might have a lemon.

[WalterBright]

Make sure the tires are properly inflated and the parking brake is disengaged. Also, drive smoothly (many people drive erratically going on and off the throttle, and emphatically deny it when you, as passenger, point it out).