I'm not entirely sure, but I think that I may have found a way to boost our PIP's fuel economy - and have cabin heat! - under certain circumstances.
I semi-regularly drive to a friend's house in a nearby city. I take my housemate's PIP instead of the Leaf because of the rough-ish neighborhood in which I park. It's about an 8 mile drive each way. (I also have another friend there who is about 6 miles away from me. I usually take the Leaf to her house.) Anyway, I usually use EV mode within the cities, and Hybrid mode (with heat in Winter and A/C in Summer) on the secondary road/highway portion, which is about 5 miles. I usually get about 72 MPG each way. Tonight, however, I used EV mode for about three miles of the highway, and about two of the city miles, absent-mindedly, also leaving the heater on, then switched back to HV mode, leaving the heat on. When I got home, the car estimated 86MPG, and I had 2.3 EV miles left, out of 10.3 estimated with the battery charged. I usually have less than 2 miles of EV range left. That's Summer range territory, not Winter. Here is what I think happened:
For several miles I used a sort-of-mode that occurs when you have the car in EV mode but also run the heat: the engine starts regularly, but not frequently, to keep the coolant hot for heat, but then shuts back off when it's warm. I don't generally use this quasi-mode because I don't want the ICE running in EV mode. However, it appears that this mode doesn't just give you heat; it also stretches out the gasoline fuel economy substantially. I wasn't observing closely, but I suspect that the computer that manages these things tries to start the ICE when it is both cooling off AND the car is going up a grade or hill. Another thing I happened to notice tonight (I may have seen it in the past and just forgotten) was that if you are traveling on a flat street - not downhill, but flat - in this mode, the fuel consumption display will still show 100MPG WITH the engine essentially idling, but running.
I know that the PIP is essentially obsolete tech now (although the overall hybrid powertrain design is still great), but for those of us who still drive a PIP, this bears further investigation. It will likely only work in mild temps (it was in the mid to upper fifties Fahrenheit tonight, but I had the heat set to 74F) and maybe even slightly warm temps, but that still covers a lot of driving. You are essentially simulating a "Super Eco Mode" by telling the ICE to only run often enough to maintain its coolant temp at optimal. The car then runs the ICE less often than when in Eco mode, which also 'steals charge' from the EV-designated portion of the battery, but these ICE warmups also add to both the range and fuel economy, by using the ICE to climb grades. A VERY rough guess on my part is that you can boost the MPG estimate into the eighties for maybe 20-25 miles of driving this way - less in hilly terrain or colder weather.
Scarlet Ember 2018 Leaf SL W/ Pro Pilot
2009 Vectrix VX-1 W/18 Leaf modules, & 3 EZIP E-bicycles.
BAFX OBDII Dongle
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