EVTripPlanner vs Model S planning and range assurance

[lennier]

In case anyone's interested I think I may have started to get to the bottom of the differences I've been seeing between EVTP's forecasts and the actual figures I've had from the car, compared with the accuracy others have reported.

I hadn't fully appreciated the way EVTP estimates and adjusts speeds on each segment of a route, and once I dug in to that detail (at least for one of the trips I took) I realised that the average speed EVTP was using for some major segments was significantly below what I actually achieved. EVTP claims to use average speed for a segment at the time you run the route plan, so clearly this can and would change at different times, which I hadn't appreciated.

Bottom line was I needed a speed multiplier of 1.1 in EVTP to get segment estimates closer to actual driving speeds, and that brought the kWh used much closer to what the car actually reported. Still erred on the optimistic side, so not a complete explanation, but at least it seems to improve my ability to predict usage and adjust for likely speed variations on major route segments.

 

[raynewman]

Over the last week I have been using a Model S 40. This obviously has quite limited range but has been modified so it can be supercharged. As I am in California there are plenty of superchargers. I found the 'in car' Nav to be quite good except.
1. The car is quite old and the computer quite slow. Took ages for a recalc which got confusing.
2. Nav had a bad habit of wanting to return to the previous charger when about 25% into the trip.
3. It couldn't find at least one of the superchargers.
This car had a max range of 132 miles; so quite limited but I managed 1,171 miles over the week relying totally on the Nav. I just don't know California.