I wasn't really thinking about it in terms of highway cruise speed, but the 47-48 miles per hour zone makes sense in that it is about the maximum speed you can maintain without the revs creeping up.
I'm finding that around here however, surrounded by 40 zones, it's difficult to drive in any remotely normal way and maintain anything over 33 mpg. At 35+, the ICE kicks on for steady speed driving, forcing one to hold it at 5 under to keep it in EV mode. Then it seems like pulsing up to just over 40 and gliding down to 35, ICE off just isn't worth much to overall efficiency.
Maybe I should petition the city to lower those 40 zones to 35.
