"B" is for......

It is motor braking. It slows down the car faster than normal coasting. Look at the manual for more information.

Posted via the PriusChat mobile app.

 

it's intent is similar to low on an automatic transmission. it uses engine braking on seriously long mountainous downhills. saves your friction brakes.
living in new england, i have never used it in 13 years.

 

You use B from the top on long steep downhills (about 600 foot vertical drop or more) to keep the battery and disc/drum brakes cooler. This is the same way you would use L in another car.

You always get lower MPG in B, but if the hill is long and steep enough, MPG is not everything.

 

I use "B" for "stealth" braking! (Think about it! )

 

wouldn't that be sb?

 

For those times you WANT to be rear ended!

 

This is the only time I use it:



Any flatland or short hill application is a waste of time, and bad for mpg.

 

P.S. Most all of these "forums" have a search function.......which allows you to see all of the previous discussion of common questions.
This is one of those questions that has been discussed MANY times before on here.

 

Toyota was too honest to call it L, since it is not a lower gear, but if they had, we would get WAY less discussion about it. It legally fulfills the purpose of an L gear.

 

...or for when my inquisitive followers want a really close-up view of what I'm carrying in the boot! "B" = "BUMP" | "BOOT" | "BUM" | "BANG"

 

if we didn't have people asking the same questions over and over, we'd be out of B = business.

 

I just never want my car to get hit, that may be a difference in attitude.

 

Afraid not. In stealth mode the S is obscured without the use of smoke or mirrors.


MERGED...



FWIW, I'd disagree with the B mode being bad for mpg when descending any hill. You would only be coasting with no ICE, or braking with regeneration. For example example, a recent road diversion puts me on a long winding decent with a 20 mph limit which is busy with mixed traffic including juggernauts. Using B I still have to use the brakes and notice that regeneration increases then, just like in D. And the friction brakes come on too when needed.

 

It could be you're noticing the greater engine breaking, misidentifying it as regen. AFAIK, B mode's express purpose is to reduce regen, with the engine-brake tactic, thus to delay having a "fully sated" battery, and the car dumping all the braking task on the friction brakes.

If this happens when you've still got miles of steep downhill still to come, you could well overheat the brakes.

But the common denominator of such scenarios is it's long downhills; a local up-and-down hill, you're better served just using the brakes. Simpler too.

One thing: all of this is just lore, cobbled together on PriusChat and a few others. Toyota's woefully quiet on the subject: a terse sentence or two, which leaves owners "talking among themselves".

 

I vote for this one!

 

The best use of B:
You are going, say 100mph and zip by a cop that was hiding on the other side of the hill.
Ouch!!!! If you slam on your brakes, the cop would, by seeing your brake lights come on, know that his radar gun was NOT malfunctioning and that Prius (!) was in fact going the indicated 100mph that his gun recorded!

BUT, if you go into B (Stealth Bomber) mode, you slow down without giving away your panic braking to the perplexed cop, who now bangs his radar gun on the palm of his left hand and shoots at you again, showing the accurate (and proper) 75mph that any proper Prius can and should achieve when pushed to its puny limits.

He sighs with relief as his mind confirms his preconceived notions about the Prius.

You go out of Stealth Bomber mode and bomb the next uphill.

 

Gosh, that's REALLY steep. I'm amazed that even the B function can cope. I'd never try to drive down a hill that steep. You must be insane!

And how do you make it back up the hill? No car could get up there, apart from maybe a Land Rover with a winch. Bits of it are beyond vertical!



Oh, wait.... Is this picture taken from above?

That's OK then.

 

It is possible to pull up the elevation changes of a route in line graph form in the Googel Earth app.