Repeated use/switching from "D" and "B" drive

It shouldn't cause any problems--but it wastes gas.

B forces the car to spin up the engine to dissipate energy.

It doesn't enhance regen.

 

It probably doesn't warm the engine up because it's not burning fuel--just acting like a big air pump to slow you down.

Use the brakes! If you do it gently enough *all* of the slowing is from regen (without actually applying the pads to the discs until you're just about stopped).

 

If you are on a hill with more than about a 600 foot drop, B may be a good idea. Other than that, it mostly wastes energy. (The rules for a PIP are different)

B under the D in the Drive gears? | PriusChat

 

With 'B', that energy is split between the hv battery and engine drag. With judicious use of the brake pedal, all of it is directed to the battery.

 

Not at all, just know you are hurting MPG. (but not the car)

 

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My former commute had a drop of almost 100 m along one particular road. The stop light before the downhill was almost at a flat point. I enjoyed accelerating using only EV, then slowly letting the hill take over, before beginning to brake the rest of the way down. I typically filled up the battery to the last bar by the time I hit the bottom, then coasted more than a km on EV through a slower speed industrial park before needing the gas again. Fellow drivers were unimpressed at my stop light behaviour though ;-)

Nexus 5 ?

 

Glad I clicked on this post, I never knew that B wastes fuel…. Good to know… Prius Chat Community is always filled with tid bits of good and insightful info

 

It can be used between 24 MPH and 7 MPH without wasting fuel, but why?

 

I thought that "B" engaged the generator... not the ICE...

SCH-I535 ?

 

I am not sure we are responsible for what you thought. Below 24 MPH, it is possible B will not engage the ICE, but it is not a sure thing. Below 7 MPH it will be friction brakes, not the ICE or generator.

 

The generators are already engaged. Shifting to 'B' increases the generator power, but above 24 mph, only part of that goes to the battery, the rest goes to the ICE to be 'wasted' by spinning the engine (without burning gasoline).

Judiciously pressing the brake pedal will produce exactly the same amount of generator power, but all of it will get sent to the battery. That is, provided the battery has room to take it, otherwise the car will still waste the excess in the ICE or engage the friction brake pads.