Driving the Trip
previous: Planning the Trip
There is an accurate way to monitor after you’ve unplugged and set off. Use the Tesla energy display trip graph. Once you start your journey, the Trip tab will show a live calculation that compares your actual consumption to Tesla’s prediction.
The Tesla energy display graph does the predictive arithmetic for you when you enter a destination into the navigation so it can account for hills and speed limits along the way. Once you’ve begun to drive the trip the green line shows you how you are doing and by extrapolation the green line provides a continuous [updated] prediction*.
*Based on this example (23 miles in to the 100 mile trip) the conditions are adverse and or we are driving beyond the posted speed limit. If we are not comfortable with this end of trip prediction (16% battery) then the easiest way to get the green back up to the gray line, if desired, is to slow down. Next time we plan we can add extra range to compensate for our lead foot driving style.
I also like the mental gymnastic of comparing trip miles to go against the range miles remaining prediction. One can verify with arithmetic. While enroute subtract the actual distance to go from the indicated range remaining. The difference will be your reserve cushion.
Perhaps your getting the idea that the range indicator on the dash is false hope and you would be correct. It is the least useful as a predictor. It serves as only a base starting point. Slightly better is the Tesla energy consumption graph. If the green line begins to diverge from the gray line then this is an indication that you are using more energy than planned. If you figure wrong or cut it close then the car will nag you to reduce speed (to conserve) or worse case recommend a quick pit stop short of your destination for an added charge.