Driving the Model S

Short trips, or long trips, it’s the perfect car: it tells the driver the range, where to charge, the traffic.

The GPS software takes into account not only the shortest route, but also the one with less traffic.

Once I saw the system change the route three times just based on the buildingup traffic, since it was rush hour: suddenly the best way was another way, and yet another one. This is the best car for someone that deslikes traffic jams, because of accidents or other causes, this car really helps avoiding them.

The Trip curve shows your Wh consumption along your driving, based on:

  • Length of the path;
  • Legal speed limits in every section of the planned trip;
  • Elevation along the planned trip;
  • The driver’s behaviour;
  • The car’s SOC State of Charge in the beginning and along the trip.

When driving, if legal speed limits are respected and accelerations are normal, not hard, in the end you will have almost exactly the SOC % it stated in the beginning. Or a bit more. The calculations are conservative. If you drive under the legal speed limits and softly with no hard accelerations, you will end with better than predicted final SOC.

Some examples of recent drives follow in the next pictures.

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Planned trip, beggining
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Same trip, soft driving, will end with 1% more of precalculated SOC. It marks where I am currently after 10 km. The curve was adapted above the original calculation: I’m behaving properly 🙂

This was a short trip just for demo purposes. A longer trip may give you much better ending SOC. The next example is a hard/harsh drive.

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Beginning of drive, predicted curve
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Lots of hard accelerations, the actual curve is under the projected curve; can you tell where the hard accels happened during the drive?
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Each hard acceleration is marked (Photoshop manual edit): an inverted triangle shows fast energy consumption (negative slope) followed by some regeneration (positive slope)

The curve is updated in real time while you drive: you are all the time in full control of the energy saving or waste you are doing. Going at 140 at a 120 km/h section gives you worse Wh rate and the curve shows that instantly plotting under the initial calculated curve. To see Wh savings it’s enough driving 2 to 3 km under the legal speed limit, if the tarmac is dry. Wet tarmac gives you bigger consumptions.

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A longer trip, 32 km long, with soft driving and always respecting speed limits: the driven curve almost matches the predicted curve

As far as I know the software is not yet applying in its calculations:

  • Air temperature;
  • Wind direction;
  • Air density;
  • Humidity;
  • Rain;
  • Wet or dry surface roads.

From these, rain and wet tarmac are the ones with most impact. Taking this into the software calculations would be a great improvement.

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