Pretty easy question. What does the "B" on the shifter stand for and when should you shift to that gear?

k

 

Unlike what my "salesman" thought, it does NOT stand for "Battery".

It stands for "Brake" and is used similar to engine braking going down long or steep grades. The manual will give you a full description of it's purpose and when/how to use it.

 

Battery"? Its good he only sells cars. Thanks for the real answer.

k

 

It sacrifices regenerative braking as an "aid" to actual frictional braking and substitutes engine compression braking. Only to be used if you think the friction brakes might otherwise overheat, say on a long downhill run requiring LOTS of frictional braking..

 

I've read a lot of posts and I've asked repeatedly if there are any negatives with B braking being used on a more regular basis. Other than the fractional amount of mileage possibly lost (I read a post by someone, somewhere that figured out that it shaves a little), is there any downside to using B on a more regular basis (for example, pulling up to a light 1/4 mile away).
I really don't care if my car gets 38 or 39 MPG (or even 35, for that matter).

 

Adding an additional comment to the previous ones:

Shifting to "B" will disable your Cruise Control. It took me some time to figure out this was by design and not a defect with my individual car.

 

Larry,

You can do the same thing as using the "B" position on your shifter by using the foot brake when slowing for a stop light 1/4 of a mile ahead. The only difference is that one (braking with your foot) will involve regenerative braking and help with the battery and the other (B position on the shifter) will use the engine to brake.

There is no harm in using the shifter mounted engine brake but you do not get the benefits of regenerative braking increasing the power stored in the battery. Is there a reason you want to do this?

 

No, not sure one way or the other.
I thought that with, somewhat rapid deceleration (such as exiting a highway) the foot pedal would use the pads (assuming a greater speed change than the regen system could provide) instead of the engine.
But since I'm not an engineer, I could be wrong.

 

Larry,

The hydraulics will engage under "hard" or "emergency" braking. If you can hear the "whine" coming from mg1 as it produces power, you are using a regenerative braking system. If you do not hear the whine, you are on hydraulic brakes. In the latter case, you might also hear the tires of the vehicle behind you just before the impact as they hit you from behind...

You can check the differences on a deserted section of road by letting off of the gas and listen to mg1 as it enters its “coasting” regenerative mode. Once that is established, try “lightly” pressing the brake pedal. This will disengage the regenerative braking system and allow the car to go into a “freewheel” mode. Nothing in the way of braking is happening at this point.

Press a little harder and the car will enter its “braking” regenerative mode. The car will brake harder and the battery is being recharged. Pressing down further to invoke a “panic” or “emergency” stop will disengage mg1 (the “whine” will go away) and engage the hydraulic brakes. You can feel when that happens.

Try to press the pedal into the firewall and the anti-lock brake system will engage. If you have gone this far, pray that you don’t have a tailgater behind you.

 

Wow, you've done your homework.
I'm aware of the 'lack of brakelight' that B produces, so I never use it when anyone is around.