What is the 'B' option in shifting used for?

It's intended to be used when going downhill for a long period of time so you don't have to ride the brake. I've only used it once. That was when going downhill for a long time on a winding road. It was useful then, but I think most people will never need it.

 

<_< 2004 Owner's Manual - Section 2-6 "Operation of Instruments and Controls" pages 135-137

This section gives a good explanation of the "B" shifter position.

The Owner's Manual is a great resource for Prius information.

 

Try this: use the search function and do a search of all forums for B mode. There is really a lot of good information on this since nearly all of us have had the same question.

 

The B position is one of the best safety features offered if you drive in mountainous terrain. It will keep the car slowed to a safe speed on a 9 degree grade. When on a long 11 degree grade we have to touch the brakes just occationally to slow down to a safe decending speed. Unless you have never had your brakes fade to nothing because of over use, you can't appreciate what a great feature the "B" motor brake is. I'm not too crazy about the Prius in general, but the "B" is one nice feature.

Doug

Doug

 

Think of B modes as a lower gear position in an automatic. It is specificaly provided to assist in controlling the car while traveling down long and/or steep grades so you don't have to ride the brake. It is also useful whenever you want to have the effect of engine braking when coming to a quick stop from high speed or whenever you feel like you need additional engine braking (hence the B).

 

I think that would a bad time to use it. If you need traction to turn, you don't want the car wasting your traction trying to slow itself down.

 

ha! I only popped into this topic because I had a bet w/myself that Chas had already posted his "RTFM." Chas, do you just paste those in by now?

rpm (in full agreement, BTW, w/RTFM...I haven't yet, but would try to not post a basic question w/o looking there first!)

 

Here's a little-known use for B. When approaching a red light, shift to B, when you stop shift to N and then to D. This will stop the ICE immediately, which otherwie may continue to run for a while. This trick does not work when the battery is fully charged and the car needs to get rid of some of the extra charge.

 

Howdy onerpm

Question: Did you PAY YOURSELF after winning your bet with yourself? :lol: :lol:

Many people are intimidated by manuals; however, there's a lot of useful information therein. Some years back (in the computer software industry), I formed the habit of highlighting manuals and writing my own 'Index' regarding subjects which seemed significant.

"Works for me.!!"

 

"B" does not interfere with traction control, and does not change the torque or power available at the wheels for accelerating.

 

It is used to avoid riding the brake when going down a long hill, dry, wet, icy, or whatever. Icy roads don't matter except that one should be going slower on ice, and therefore one would want to shift into "B" sooner than when on a dry road.

 

no, because I already owed myself money from a previous bet.

I used to be an avid manual reader but now they turn me off - the poor translations (espec. the NAV manual), the sheer volume of silly warnings
"!!! WARNING -- KNIVES CAN CUT!!!"

etc.

I do wanna scream when I seem some of the posts on here, but I know you're always there to set them straight!

rob

 

Howdy again onerpm (Rob)

On risk of hijacking this thread... APOLOGIES to the thread.

Agreed on the "less than excellent translations!" It has always puzzled me why offshore manufacturers don't employ U.S. natives to write their manuals - would lead to much happier end users.

I hope my encouragement to "Read the Manual" are taken as constructive rather than critical. Even with the poor translations, there's a lot of useful information available on both the "Official" Manuals and on John's "Manual." Perhaps a good new thread would be "About the Manuals" -or something similar.

 

Howdy again.
OK, this is my second-last post to this thread.

But...you know who translated the Prius manuals, don't you?

(answer to follow)

 

rmarchena

 

I'm talking about actual traction. You want full traction helping you steer if you start to drift. To get that the wheels need to be free rolling. With "B" it sounds like they would not quite be and any slowing down they were trying to do would take it's share of available actual traction. If TRAC does that automatically, then cool!!!

Otherwise I'd want to be able to release the "slowing down" as quickly as possible, which I would think would be by being able to just release the brake pedal.

I guess I'm just saying know your traction or friction circle.

 

Cool!!!

 

Now I see what you mean. I can't prove it, but surely the anti-slip system works just as well in "B" as it does in "D". The only alternative is to shift into "N", which would be a really bad idea.