Hi,
This is a bit like the old joke from the college physics exam:
"Define the universe and give three examples."
But there is a somewhat serious side to this question.
TYPE A - idle off
Let us say we take a standard car like my wife's Echo and equip it with a circuit that does the following:
1) when stopped and the foot brake on - turn off the engine
2) when the foot comes off the brake - automaticly start the engine
A) Has my wife's car suddenly become a hybrid?
TYPE B - engine assist
Let us say the alternator on her Echo is modified so it can run as a motor as well as a current generator. Then we add a circuit to do the following:
1) when accellerating - make the alternator into a motor to assist the ICE
2) all other times - work like a standard alternator
B) Has my wife's car suddenly become a hybrid?
TYPE C - parallel
Let us say I add a retractable, 5th wheel, an electric motor/generator, with a separate battery power and control system. Then we add a circuit to do the following:
1) at speeds below 10-15
mph - the engine remains off and the 5th wheel provides motive power and regenerative braking
2) at speeds above 10-15
mph - the ICE starts; the 5th wheel retracts and the vehicle runs on ICE power
C) Has my wife's car suddenly become a hybrid?
SUMMARY:
Type A - suppresses idle
Type B - power flows in series with the ICE so ICE must turn to use electric
Type C - power flows independent of ICE so ICE can be off yet vehicle moves
A key componet has to be automatic operation, leaving it to manual control would define all vehicles as "Type A."
Bob Wilson