A 4th point and possibly only relatable to European owners, the CHG mode ensures that there's enough battery charge to travel within city limits or districts where the car must be in EV mode. A side benefit for CHG mode is if you arrive at a destination without charging but wish to use the battery for pre-heat or pre-cool. This one is not about efficiency but it's more for comfort/convenience.
Even if Charge-Mode seems slightly inefficient,I can't praise Toyota enough for implementing it ! I will definitely make use of it !
What I mean is this. Take a look at this graphic from this Toyota video. If driving puts you in the lower-left corner because torque is really low, as it would be at low speed or on a gradual downhill stretch, charge mode could put you up closer to the red area. When I tried charge mode on a Prime, rpm noticeably increased, indicating to me that it tried to follow that blue curve up and to the right. If that thermal efficiency increase is sufficient to overcome the losses from generation and battery in-out losses, there could be an overall advantage. Of course, we'd need numbers of the above charts, and knowledge of the system losses to make that determination, and we have neither of those so this is just a possibility without testing.
Model I have is the Prime Plus, the basic model. Bisco Do you expect Toyota to answer this ? The answer may be profuse in the math of ME and graphs and cicumstantial variations. Just be happy, ITS CHARGING.
@Andyprius1 please use the multi-quote function. It's much easier to read and saves space. Thank you.
The yellow area inside the red one indicates the new +40% thermal efficiency (the "raise" part of the statement). This indicates to me that even if you are inside the red area but to the left to the yellow - charge mode will increase thermal efficiency, this may expand to 'moderate speeds flat ground'. I suspect that in charge mode the charge rate is constant (irrelevant of speed), so a simple test when the car is stationary may reveal this rate and the time required to charge from 'empty' to '80% full'.
Well, I am with Mister MMT here, would like to know! If it is speed related, then at several constant speeds.
hv charge amps for the gen 4 hb using scan gauge. ScanGauge II – Prius Gen 4 XGauges – Observations on Hybrid Battery Current | PriusChat
And, also, even the Liftback is capable of bringing engine demand high enough to get more efficient, and then cycle the ICE and run on battery for a while. It's far less likely to do that when cruise control is enabled, but I've seen it kill the ICE as high as 73 MPH.
