The mysterious "B"

Well, I'm sure that most of us have asked the question at least once....so the poll is a little misleading.

For me, I called toyota directly because my sales rep told me it was a "backup" switch. I said that was "weird" (nice talk for "stupid") because there was a "R" for reverse already.

 

Engine braking. No regeneration advantage, but helps you keep off the physical brakes.

That being said, I'm rarely in a situation where I have to use them for anything.

 

No Mr. E

 

Welp, it depends on the time frame.

When I first bought my Prius, I DID NOT immediately know, until I either thought about it for a while, or found out here. It's not an intuitive thing...

 

I think there is some regeneration in the 'B' mode. I have two purple bars when I start off in the morning. By the time I get to the freeway I have 8 green bars and I always use 'B' mode so I don't have to use the brakes.

 

It's more or less the equivalent of shifting into the "L" or "2" selection on an ordinary automatic tranny, basically low gear. For coasting down long, steeper inclines without accelerating, or riding the brakes.

 

The B is an abbreviation for "bugger" which is what you say when your knee hits it and the cruise control setting turns off.

 

I live in the Whatalyer mountain range in Indiana, and frequently use B, though it is quite annoying to have the cruise pop off.

I also have no clue why Toyota would design a car that "forgets" what the cruise speed was set to just because the car temporarily slows below 24 MPH. Most of my driving is in a semi-rural area where the traffic lights / stop signs are one mile apart, and I have to keep setting the cruise to 38 MPH every mile. (38 seems to maximize my EV mode.)

 

Okay, "B" does give more gegeneration than coasting, use it for slowing down or long downhill runs where you want to keep the speed down.

As for the cruise control. Toyota designed to to lose its pre-set so that you have to manually accelerate to your desired speed as opposed to just clicking in the resume.

The thinking behind this is that as a driver you would accelerate slower, the cruise would detect that you have a pre-set of 110kmh and hammer the car to get there.

Mark

 

way too funny...........ur sick!

 

Hi Mark

B mode does give more regeneration than coasting with the brakes off; but it gives less regeneration than gentle braking does. This was clearly established long ago by Wayne Brown, who in fact produced a table showing the amount of regeneration (in Ahr) produced by B, coasting and several levels of braking. I no longer have the table, and all I can remember is that gentle braking (50mph to 0 in about 30seconds) was most efficient of all. Hard braking was worst, followed by B, then coasting...

Your theory about Toyota's thinking re cruise control is presumably just that - a theory. My own theory is that there are just too many circumstances in which accelerating from a very low speed or zero, no under driver control, would be potentially dangerous. It is a safety, or "anti-litigation" measure...

Jerry

 

Was his table on the Classic, or the 2G? 2G changed the braking system quite a bit, which may also affect B. Classic used some friction brakes at all times when applied, where 2G waits until actually needed.

 

While I know it is a ower gear for battery recharge on steep declines without the brakes, I enjoy telling people that when I move it into "B", that a booger flicks out the back of my Prius and onto the windshield of the tailgater behind me.

 

That's good, but I think I will tell people that D is for Drive, B is for Backup and R is for Race.

That is if I get my Super White 06/06 Monday from DeLand (FL) Toyota as promised!


Regards,
Steve

 

You are going to let them drive it after you tell them that, right? :lol:

 

"Whatalyer mountain range in Indiana" Inteesting! I grew up in Ohio and drove all over the Mid West when young and had a chance to see Indiana, Michigan, Ohio mountains. I even skied on a few. Then I moved west. That was then this is now. I have to say I have never seen a "mountain" range in Ohio, Indiana, Michigan and Illinois. No disrespect but everything is relative, and a mountain has snow on it 24-7- 365.