Actually, wanted to discuss this with u all.

In our and Prius's case, we convert mainly petrol > battery, while some is saved from regen braking. From personal driving, I'll say maybe 20% of the battery's power came from regen/braking.. (I consider myself a pretty good hypermiller, avg 19.5km/l for 80% city, 20% hw)

My question is, as physics says... During conversion of energy from 1 source to another, definitely energy loss will happen.

+ We're carrying the extra weight of the battery and the IMA system itself.
+Prius, even worse, carrying two full set of engine and transmission thingy and battery.

By this logic,
Wouldn't it be more efficient if we just have a 1.5L ICE in Insight with start stop tech, which i believe is the main contributor to our FC? (The new civic non hybrid have an eco save version with autostop feature too and their FC is similar to ours~!)

In terms of converting the energy to electric (energy loss), storing it(energy loss), using that energy(energy loss) and convert it via the electric motor.. + the added weight of batteries, I guess we're really in a small sweet spot that makes it all worth while in the end.

Now, going into the petrol>battery deeper, wanted to ask if there's RPM ranges during the ICE combustion where it's actually more energy effficient to convert and store into battery vs, burning the ICE 100%?

For example, if I drive at 40km steady, u will notice it'll charge battery, and after charge a few seconds, it'll go into EV mode, then depleted, then charge, then EV mode again, etc for infinity..
Apparently, overall this operating mode is more fuel saving in the end, despite, the initial assumption that converting energy from one form to another will result in net loss?

Anyone else finds this interesting on how the engine works, and why it's possible to convert and still net gain in the end?
*My unscientific guess is, at certain RPMs/Speed, the energy gained from burning ICE and the conversion ratio of that energy into actual speed is not efficient and results in huge losses*

And, during this highly energy>speed 'defficient' speed/rpm range, it's actually more profitable to convert the energy to electric save it and use it later on....

Because a series-hybrid omits a mechanical link between the combustion engine and the wheels, the engine can be run at a constant and efficient rate even as the vehicle changes speed. The vehicle speed and engine speed are not necessarily in synchronization. The engine can thus maintain an efficiency closer to the theoretical limit of 37%, rather than the current average of 20%.[3] At low or mixed speeds this could result in ~50% increase in overall efficiency (19% vs 29%). The Lotus company has introduced an engine/generator set design that runs at two speeds, giving 15 kW of electrical power at 1,500 rpm and 35 kW at 3,500 rpm via the integrated electrical generator.[4]