I tried the CHG mode once on a long road trip last summer in my ‘21 Prime to see how it works but couldn’t think of a good reason to use it again until today. I had my usual 100 mile/160 km drive home from work and, with EV Auto mode at 120km/h (indicated) set on cruise control, I had about 10 km left on the GOM. I immediately had to pick up my son and drop him at scouts (will have to pick him up in about 90 mins) and it’s about -10C at the moment. I decided to engage charge mode to increase the GOM to a range that will be enough for a round trip EV only mode to get him later. I don’t currently have an L2 charger at home and I’m limited to 8 amps on my outlet, so a traditional charge wouldn’t have cut it. Consequently, I reasoned it would be better to pay the slight fuel penalty with an already warm engine to avoid firing up a cold engine two hours later. What this really means is I should get an L2 charger for these situations (they’re more frequent than I thought they would be), but in this particular circumstance, I think it justifies the CHG mode.
prius is pretty good at keeping the coolant warm. it would be interesting to know the temp after 2 hours at -10c
@bisco it's sure not a full warmup cycle, and ICE will stay off it coaxed gently, depending on how warm the car was before it sat for those 2 hours, talking about the prime, so others aren't confused. @Ovation there sure are some times when CHG mode is convenient ! I posted a very similar situation the first year I owned the prime, needing to have a fuill charge for the other driver within an hour or 2 and only having the OEM EVSE at 110 volts to charge with. Seems, back than and possibly even now, new owners are more in tune with EV than that lowly HV mode and anything at might reduce MPG's by 5 or 10 mpg (for a 25 to 50 mile trip), even when used without knowing what contributes the most to the losses. I don't use CHG mode to much,, but I'm not one of the PC members that thinks CHG mode is completely useless either,
The thermos disappeared in the gen3. At that time, Toyota got engine warm up fast enough that they no longer felt the need to take steps beyond what they do for other models in keeping the coolant warm.
After some experimentation, my conclusion is that CHG mode efficiency when combined with the use of EV mode from the CHG result in the same or very similar efficiency as HV mode. Can using CHG Mode be more efficient? | PriusChat Knowing this result, I would use CHG mode on my very cold morning commute when I know the engine will come on anyway because of the temperature. I use to drive most of the winter morning commute in HV mode using engine heat for warming the cabin and saving the EV range for my afternoon commute which was just enough for one way. But now, I don't commute daily. I only drive to work once or twice a week and not usually in the early morning. Plus, I now have the ability to charge on an L2 charger at work which was not available before. Thus my current strategy is if the temperature is above 14F (-10C), and I have enough charge in the traction battery to drive in EV mode entire 18 miles, then I try not to use the engine. If the battery is low and the temperature is also low, then I will try to use CHG mode to quickly warm up the cabin and use the EV mode later after the cabin warm-up as long as there is room in the traction battery to use CHG mode. If the traction battery is full, then CHG mode will not give me any more useful EV range, in that case, I will stick with HV mode.
What's your question Troll? Does Prius keep it coolant warmer than any other ICE car on the market? or Why is Bisc curious about how much heat loss there is in the coolant in a Prius @ -10 C ?
