Electric cars

In my normal driving I don't make many fast stops. Prius has smaller than normal brakes because of regenerative braking. And the city mpg (stop and go)is better than highway. Regeneration must be quite effective.

I read Prius wants to keep battery charge between 40 and 60% of capacity because it gives longer battery life (NiMH). I suspect on a long descent they would run it up to 100%.

There is no benefit to a hybrid at highway speeds because the engine has to run anyway. .,..and you're lugging the weight of the batteries along for no benefit.

I would seem to be a *LONG* descent charge .4C or the batteries are too small to be of much use.

. You can use a smaller engine, with battery/electric motor added for when you need more power - acceleration, ascent. (For a very long fast ascent where battery assistance is required you can run out of battery.) The smaller engine operates at a more efficient point. The benefit - around

And with a conventional car you are lugging the weight of the higher horsepower of the engine that is not being used most of the time.

In a Prius, at higher speeds the engine - through the transmission - does not turn the wheels fast enough. One of the 2 electric motors is used as a generator feeding the 2nd motor. That operates through a planetary drive to increase the wheel speed. [See Hybrid Synergy Drive in Wikipedia.]

The engine, by the way, is a variation that uses an Atkinson cycle (which I had never heard of). .

. Design of anything is a series of trade-offs.