Originally Posted by Cobb
There is a gap or jerk when the ima checks out and lets the engine take over and it does the regen thing.
I still stand by my original theory that if you decide to drive the car inefficiently, the ima system decides to use this excess engine output to recharge the battery.
If you drive any of the prius it does this weird thing where it charges and assists all at the same time or so it looks like. They got the E CVT hand off down pack so its not that noticable at all as it switches between engine, assist and regen all at the same time.
Yes, I've noticed the small jerk when the ICE cuts in. When the ICE shuts off, there doesn't seem to be a jerk, but there often is when the ICE turns back on.
Whenever I'm driving, I'm often thinking about what is the best strategy for determining when and how quickly to recharge the battery. Cases like braking and deceleration are obvious, and the battery always gets charged at those times (unless it's already full), but there are also times when the IMA system scavenges engine power to charge. Sometimes it seems to me that it should do more scavenging, and sometimes less, but the computer can't know what's ahead, so it has to use some algorithm that tries to work well over a wide range of terrain and driving styles.
I definitely want to look into the PHEV kit, as it seems like has the potential to pay for itself after a few years of driving, but it would be nice to customize it so that as much of it as possible can be placed under the rear deck next to the spare tire, where all that styrofoam is right now.
Yah, the Prius is a different animal. I've never owned one, but my impression is that it's a more complex system. I think it has two motor-generators, which probably explains why it can charge and assist at the same time, acting almost like a series hybrid at times. The motor-generators are also not as tightly coupled to the ICE as the IMA motor in the Honda system. All this extra complexity and ability to act like a series hybrid at times seems to give the Prius a big MPG advantage in stop-and-go city driving. The Insight 2 performs pretty poorly in heavy stop and go driving. Fortunately there isn't much of that where I live, but one time I was down in LA and my mileage for a stop-and-go segment during rush hour was 38 MPG. That's still a lot better than an ICE-only vehicle, but it's less than the EPA estimate of 41 for "city" driving, and far less than the Prius is capable of in similar conditions. The PHEV kit probably helps a lot with that by keeping the SOC high so that the IMA can use more assist.
Of course, there is a cost for the extra complexity of the Prius system, and they cost around $3000 more than an Insight with a similar trim level.