animorph
Active Member
From what I remember the most efficient speed for travel is around 25 MPH for an EV, in terms of Wh/m. At freeway speeds, if you want maximum efficiency then drive as slow as you can.
As a practical matter during long interstate trips we drive our old normal +5 - +9 MPH above the speed limit. If we find the charge remaining at destination dropping to 10% or below we slow down, starting with 3 MPH slower than our current speed. That's usually enough to increase the charge remaining at destination. Reducing your speed is a great safety margin that you can control very simply. Beyond that we might follow semi at our normal following distance to further reduce our wind drag. We drive an X, so aerodynamic drag is fairly high, and increases quickly with speed as noted in the above posts.
The advantage of this speed effect is that if you get caught in slow traffic, your range may actually increase. Some of our longest driving stints were made possible by slow Los Angeles traffic! We may be able to skip a supercharger unexpectedly. So no worries about traffic.
You can experiment with A Better Route Planner settings to see if a faster or slower driving speed plus more or less charging time will get you somewhere faster. Back when I last looked at it, the fastest overall time was to drive as fast as possible. That also assumes you charge to a reasonable percentage of capacity, not 100%. It's an interminable wait if you have to charge above 70% to 80%.
As a practical matter during long interstate trips we drive our old normal +5 - +9 MPH above the speed limit. If we find the charge remaining at destination dropping to 10% or below we slow down, starting with 3 MPH slower than our current speed. That's usually enough to increase the charge remaining at destination. Reducing your speed is a great safety margin that you can control very simply. Beyond that we might follow semi at our normal following distance to further reduce our wind drag. We drive an X, so aerodynamic drag is fairly high, and increases quickly with speed as noted in the above posts.
The advantage of this speed effect is that if you get caught in slow traffic, your range may actually increase. Some of our longest driving stints were made possible by slow Los Angeles traffic! We may be able to skip a supercharger unexpectedly. So no worries about traffic.
You can experiment with A Better Route Planner settings to see if a faster or slower driving speed plus more or less charging time will get you somewhere faster. Back when I last looked at it, the fastest overall time was to drive as fast as possible. That also assumes you charge to a reasonable percentage of capacity, not 100%. It's an interminable wait if you have to charge above 70% to 80%.