While Driving in slow traffic on a slight downhill, when I released the brake without pressing the accelerator, I wanted to coast downhill, but the Prius uses the Electric Motor, MG. If I press the brake the MG stops driving the wheels and regens the battery. I shifted to B, but it still used the MG when I released the brake. Why does the Prius use any energy to move the vehicle when in the B mode?
basicly that's the hill-holder function at speeds less than ~7mph. It's a very tiny drain at that speed. Read Hobbit's link for B-mode info...basicly though you shouldn't ever need to use it on any but the very longest highest steepest mountains.
The Prius HSD is designed to mimic a "normal" engine and drive-train so as to not be confusing to all of us well-conditioned drivers. When you let up the gas pedal on a conventional car, engine drag retards forward motion. The Prius mimics this by applying a little regen braking in the same situation. To avoid this, press the gas pedal slightly. There is a sweet spot without regen or thrust where the car will just glide. Tom
On a slight downgrade through a town, I like to apply slight throttle to put the Prius into electric mode. Electric mode is often useful at maintaining speed on downhill grades. This is a good thing, as I can travel for a mile or more using no gasoline at all. Harry
