MPG in Hybrid Mode

So, I took another pic this morning. This is similar to what you have described. An arrow from unlit engine is going out to the motor only. This pic was taken right after switching to HV while still EV SOC remains similar to the last one with arrow going to both the motor and wheels. Only difference is that at this instance, I did not have my foot on accelerator at all, so the car is coasting. Obviously there is no energy applied to the wheels and regenerative braking is charging the battery indicated by the green arrow from the motor to the traction battery. Is this what you have seen?

 

Yeah, the pic was during engine warm-up immediately after switching from EV to HV. I will see if I see anything similar happening on my long trip this weekend. When I mix EV and HV on short trip less than 40 miles, I try to keep the engine warm so that I don't have to go through the warm-up cycle more than once. But that is not always possible. After switching from EV to HV, and initial engine warm-up is complete, if you switch back to EV and stay on EV long enough, ICE will cool sufficiently so that if you go back to HV second time, it has to go through another warm-up. I am not sure if I stay on HV only long enough, do I ever see the engine icon un-lit and still showing arrow coming out of it.

I might have seen the case you described "the engine icon is lit when none of the three outward channels is lit up with orange", but can't say in what situation. It could well be the lag period after the engine is warmed up as you said about to catch up and go off. I will watch for those events as well for my next long HV drive.

This morning my EV range on GOM was 36.1 miles. New record for me. My actual EV range yesterday was ~35 miles give or take 1 mile error for there is no easy way to measure actual EV range when you switch EV-HV back and force.

 

My interpretation is the same as the one we have discussed above on the "lag" things, where the engine light is about to catch up and go off, but in this case, engine went off before the charge arrow. Or did the charge arrow continues on for the duration of time you sat at the stoplight? I can't explain it. In any case it is usually very brief for those strange combination of arrows and engine icons and EV icons are on or off. Maybe the computer inside of the car is not that smart after all, and getting confused just like us??? LOL

 

I watched the video you linked. Even though it seems to be published by Toyota as a part of technical PR, I do believe it is wrong. I think it is just simplifying the technology trying to explain it to lay people. I am no expert nor claim to be knowledgable about all the technical aspects of the Prius Hybrid system, but all of the technical explanations and information I have read state both MG1 and MG2 are motors as well as the generators. There are no separate motor and generator in the car. What the video diagram labeling "motor" is the MG2 which I believe is the main traction motor, but it is also a generator that captures energy by regenerative braking. What is labeled "generator" in the video is the MG1 which act more as a buffer between MG2 and ICE, and can also dual-function as a "starter" and "alternator (generator)". I might be totally off, but that's my understanding. I hope someone more knowledgable than I will chime in.

 

Do Google search. You will get plenty of information, I always start with Wiki for an overview. Although most of information you find about PRIUS Hybrid system online may not be specific to PRIME or the latest generation of PRIUS (Gen4), I think the principle of technology is very similar throughout generations of PRIUS in terms of how MG1, MG2 and ICE work together. Hybrid Synergy Drive - Wikipedia
Also the video Jerry put on this thread is extremely informative. If you like to read the technical paper, this may be of some use, though it is beyond my comprehension or interest. http://www.ae.pwr.wroc.pl/filez/20110606092430_HEV_Toyota.pdf

 

This is about the ultimate in detail. It's a couple hours, but it's like going to school on your transaxle.

 

Thanks Jerry. It will be my summer project to watch this video. 2 hour of technical lecture is not for a faint heart.

 

Please post a Cliffs notes version after you watch, to save us each the 2 hours.

 

That's if I don't fall asleep middle of the lecture. Growing up as the golden ages of MTV generation, any video longer than 3 min is usually beyond my attention span.

 

This one is more easily digested. Bottom line is that M/G 1 is where the magic really happens.

 

Yeah, that's the one you posted earlier on this thread in your comment #158. MPG in Hybrid Mode | Page 8 | PriusChat It was still long for me, but I did finish watching that one!

 

Oops! I guess that after a couple hundred posts in a thread some of us start to lose track.

 

Yes, I think ICE while going through the warm-up cycle has reduced power but still sending some energy to the wheels and motor. At least during the warm-up cycle even after you run out of EV range, traction battery will keep providing power to the wheel. How long the warm-up takes seems to depends on ambient temp and maybe some other factors. I have had the warm-up to finish in less than a few miles in some day, but occasionally take much longer.