Who Uses the "B" Setting on the Shift Lever??
 

I haven't found it mentioned in the posts here but just wondered who uses it?

It seems to engage the stronger regeneration just without some brake pedal applied. Guess it might get back a tiny bit more energy? Also wondered if it lights up the brake lights when you pull the lever back and use it -- don't need a tailgater in my trunk! :omg:

Re: Who Uses the "B" Setting on the Shift Lever??
 

Ohh, never thought of that. If a cop is around 'B' might slow you down without attracting attention.

Donald

Re: Who Uses the "B" Setting on the Shift Lever??
 

salesmen told me B was for driving strickly on battery and said that is what B stood for, and he said I could jump the 12 volt battery from the large high voltage battery. Both statements are wrong lol

Re: Who Uses the "B" Setting on the Shift Lever??
 

Lol i am confused, so what exactly does the B setting do?

Re: Who Uses the "B" Setting on the Shift Lever??
 

Engine braking with foot off throttle.

Re: Who Uses the "B" Setting on the Shift Lever??
 

My understanding is that shifting to "B" is somewhat equivalent to downshifting in a normal car. It is intended for use when driving down a steep grade, like down a mountain. I believe the manual called it "engine braking" mode.

Re: Who Uses the "B" Setting on the Shift Lever??
 

I live in a hilly area and have tried the "B" mode several times to save my brakes (I hate using my brakes), but it slows the vehicle down way too much (which I hate even more ;) ). So personally I have no use for it.

Re: Who Uses the "B" Setting on the Shift Lever??
 

I actually have one place I do use it. There is a very steep downhill where the speed limit is 35 near my home. Shifting into 'B" slows down the car enough that I'm not doing 75 when I hit the bottom of the hill. But other than that it's more of a pain than anything. If it had been designed for an easier shift (say drive by wire paddle shifters on the steering column) it might have been more usable. But the point of an automatic transmission is that you don't shift, so I don't think many will use it.

Donald

Re: Who Uses the "B" Setting on the Shift Lever??
 

The B setting will use the engine to slow you down when you're travelling down a steep hill. However, since it's using the engine you actually get less regen braking rather than more.

Re: Who Uses the "B" Setting on the Shift Lever??
 

I don't use "B". Are you sure it actually uses the engine or does it possibly add some "torgue" to the generator to increase resistance and thus increase generation? I thought someone had shown graphs with increased generation during B mode operation. I don't know but am curious.

I prefer to create power on long grades and have "rode" my brake pedal, probably annoying to the person behind me, but still justified since I would have broken the speed limit significantly if I had not.

Re: Who Uses the "B" Setting on the Shift Lever??
 

traveling between las vegas and los angeles regularly...i use the B on the steep grades...i like it

Re: Who Uses the "B" Setting on the Shift Lever??
 

I use B position regularly, even just slowing down at intersections or coming to a stop. I don't think B mode works as an electrical retarding brake as i use on the 250 ton off road trucks i operate, rather its on engine brake, using the engine as an air pump to slow forward progress and saving your brake pads and rotors.

Re: Who Uses the "B" Setting on the Shift Lever??
 

Joe,

I'm not sure. I thought that there were problems running the generator at high speed, so the ICE had to be used. I know it was covered in a different thread a couple of months ago.

Re: Who Uses the "B" Setting on the Shift Lever??
 

You are wasting your potential regen braking, a definite hybrid driving style no-no. If you learn to apply your brakes gently you can get battery charge for your momentum instead of heated compressed air without wearing out brake pads.

I'm pretty sure both, or either depending on the situation and how the computer chooses to respond. I'm with you on the gentle riding of the brakes for max regen. I'm sure those behind you think you're burning up your brakes pads and think less of you, but the truth shall set you free...

Re: Who Uses the "B" Setting on the Shift Lever??
 

I use the "B" setting quite often.

Living atop a hill in central Seattle, I am always heading down a steep hill on the way to the freeway or to the city's core. And the "B" setting really helps.

Re: Who Uses the "B" Setting on the Shift Lever??
 

If the hill is steep enough that you would have to use moderate to heavy braking to prevent over-speed, then absolutely this is what "B" is for. There will be a transition point unique to each situation/hill that a driver must decide between getting max regen or moving to protect brakes from wear and/or overheating.

The all wheel drive HSD cousins get to do regen braking on all 4 wheels, they probably have more leeway for regen down the steeper hills then the TCH.

Re: Who Uses the "B" Setting on the Shift Lever??
 

I often use B in rush hour traffic to hold back my speed while creeping along under 20mph going downhill. Oddly the ICE stays off in B mode unless my speed increases beyond 20 MPH or so.

Re: Who Uses the "B" Setting on the Shift Lever??
 

Just picked up my (my wifes, mostly) TCH Sat. 100 miles on it now, so new to this. I too was wondering how "B" worked. Questions:

1) does anyone know if the ICE is actually running or is it just really an air pump to add to the drag?

2) The Manual states (not in front of me now) that one should not operate in "B" for long periods because this will reduce mileage, which kind of indicates it is running?

3) If this is so one might want to operate in "B" at the start of a cold day to heat the engine as ICE are a lot more efficient (stated by Ed Wallace, Radio Car Guy who was testing the Lexus Hybrid) when they are warm?

Suggestion to Toyota that they need a section in the manual for all of us curious teck-o nuts

Re: Who Uses the "B" Setting on the Shift Lever??
 

Like the Prius the TCH stores hot coolant in a thermos bottle when shut off. It uses this to jumpstart the engine warm-up process.
My TCH goes from start to operating temperature in about a city block. My wife's XLE-V6 takes 2+ miles.
From what I remember the Prius can store coolant at operating temperature for a week even in near zero temperatures. I'll assume the TCH can do the same.
Gotta love it.
J

Re: Who Uses the "B" Setting on the Shift Lever??
 

It will not use extra fuel if that's what you mean when used for slowing down. The engine may or may not be running according to other parameters, but using "B" does not use fuel in itself. The reason the manual warns of reduced mileage is due to:
1) Reduced coasting meaning more need to accelerate back to speed.
2) Possible reduced regen braking, meaning more need to run generator.

Re: Who Uses the "B" Setting on the Shift Lever??
 

I use the B setting when I want to slow down, but don't want someone behind me to see brake lights being applied. i.e. highway patrol

Re: Who Uses the "B" Setting on the Shift Lever??
 

You jerk that baby in B at highway speeds?????????????Just may be picking up the power divider off the pavement one day lol.

Re: Who Uses the "B" Setting on the Shift Lever??
 

Because of the CVT, I don’t think there is a problem putting the car into B-mode at highway speeds. You are not asking the transmission to engage into a different gear like a standard transmission. In fact, page 163 of the owners manual talks about using engine braking at high speeds, and nowhere does it say “not recommended” or when not to shift into B-mode (i.e. do not shift into B-mode if traveling at more than 50mph)



During high speed driving you may feel that engine braking is less effective than that of conventional vehicle.



Although I think that last word is a typo and was supposed to be “braking”.

Re: Who Uses the "B" Setting on the Shift Lever??
 

I am curious whether there really is a thermos-like storage bottle for the warm coolant in the TCH. I had read elsewhere that the TCH does NOT have this feature like the Prius has.

Re: Who Uses the "B" Setting on the Shift Lever??
 

Growing up in MD, I always used the lower gears during the winter, like 2 and 1, and so will probably be using B in the winter here in Columbus when it's snowy and slippery. The boyfriend's dad was convinced that "B" stood for battery mode too. Hahaha.

Re: Who Uses the "B" Setting on the Shift Lever??
 

I use the "B" setting when I want to slow down quite frequently. I have a one mile downhill drive from my house, it saves the brakes since the momentum builds in that situation. I waited a few weeks before I was brave enough to try. I also use it when exiting the freeway as well. Love my TCH.

Re: Who Uses the "B" Setting on the Shift Lever??
 

it saves the brakes

I thought we all determined unless it was a panic stop you don't save the brakes until you get below 12 mph. When you apply the "brakes" in the TCH you are actually encountering resistance from the generator to slow down and thus charging the battery. That's what it's all about - free energy.

The hydraulic brakes (brake pad wear) are not typically involved in most gradual slowing procedures.

Re: Who Uses the "B" Setting on the Shift Lever??
 

You just may be right. If it is omitted, something sure gets the engine up to operating temperature mighty fast. It takes about a city block for the temp gage to get to about 9:00 o'clock.
I do NOT hear a pump running as I did in the Prius after startup and after shutdown.
J

Re: Who Uses the "B" Setting on the Shift Lever??
 

By using B, am I actually recovering any energy at all? The most knowledgable sales rep we spoke with said it recovers more energy than braking. I've always used engine braking to slow my other cars down and save on the pads, so it's a hard habit to break. I don't want to keep down shifting if the brakes are more beneficial.

I can hear a whirrring sound when I press the brakes. Are the pads actually being used first during the light steady braking or is something else happening?

Re: Who Uses the "B" Setting on the Shift Lever??
 

I'm not sure how long a city block is, but I can be 1 mile from my house on the way to work around 9:00am, come to a full stop at a red light and watch the MPG meter peg itself at 0 MPG while no energy transfer is shown on any of the "Energy" screens. It drives me crazy to see that happen! :confused: My entire commute to work is only 3 miles so those seconds spent at 0 MPG really hurt my overall gas mileage.

Re: Who Uses the "B" Setting on the Shift Lever??
 

I have used "B" mode only once when decending a steep grade on I-75 Southbund out of Chatanooga mph was at 65 and increasing to 80. "B" mode slowed it down quickly. I am certain if the speed was too fast for this the computer would not let it engage.

Can't think of any place it would be needed in Florida, not even on thrill hill;)

As far as having a thermos bottle, I concur that is only on the Prius. The TCH has an electric heating element (I think) to rapidly bring the coolant up to operating temperature but not sure if that function is available without the climate control set to a high temperature requesting heat.

Re: Who Uses the "B" Setting on the Shift Lever??
 

The "B" mode is the same as downshifting a gear with a manual transmission, thus allowing the transmission to "hold back" the engine's power while coasting down a slope. Great for safety reasons (no runaway car on steep slopes), but has little to do with fuel economy.

Re: Who Uses the "B" Setting on the Shift Lever??
 

I live two miles up a steep-ish mountain in CA. That gives me plenty of practice with B mode. When starting out cold, B mode spins the ICE without gassing it, but it lubricates and warms it naturally from activity and compression in the cylinders.

From the outset in B mode, mileage is virtually pegged at maximum.

By the time I've gone about half a mile, switching to Drive shows it to be at its most efficient. By this point the mileage shows about 70 ish averaged.

If I start off in Drive, the first half mile or so brings constant wheel braking/regenerating for the whole distance, but only shows as about 30 mpg. Obviously, the engine has been sucking some gas to warm up and get ready to ramble.

Coming down the west side of the Rockies during a road trip, I used it to bleed energy on endless downhills when it seemed that constant foot braking might be detrimental, should overcharge conditions cause brake-only slowing.

The theory being that once the batteries are full to the brim, the brakes no longer divert energy into the battery, so they either spin up the ICE to bleed energy (and you can hear it whine when that condition kicks in) or put the entire weight and momentum on brake pads, potentially leading to fading. Instead of that, the B mode was selected, and although the ICE whined in fast-spin mode, a comfortable 60 was maintained for miles and miles with no apparent issues.

My conclusion is that B mode is really only helpful down hill. And only when engine braking is obviously a Good Thing. It extends my milage when the car is cold, but doesn't seem to change the overall charge level's point of full up as I continue down hill.

Now that I see the questions posed here, I'll try it in other ways to see if different behaviors from my habit will produce consistent alternative results over this two mile test bed.

Re: Who Uses the "B" Setting on the Shift Lever??
 

Never!

Re: Who Uses the "B" Setting on the Shift Lever??
 

Wow -- so much confusion. The B mode is designed for long down-hill descents. Once the traction battery reaches its maximum allowable state of charge (SoC), without the ability to shift the "empahsis" to engine braking, the friction brakes would be forced to bear the entire load themselves, as the drive system in its normal operating mode provides little, if any, actual engine braking. I don't know the numbers for the TCH yet, but in the Gen-II Prius, which I used to drive, the ECU would not let the traction battery SoC exceed about 80%. If you're still screaming downhill after the SoC reaches that level, you're going to suddenly be on the friction brakes alone. At first, this confused me, until I realized that in the conventional cars, you always have the engine braking effect present; in the HSD cars, you lose the generator drag when you hit 80% SoC.

Of course, I live in FL, where the highest elevation is about 350 feet MSL, so it's a moot point for me -- B is useful, however, for brake-light-free decels (preceded of course by a look in the rearview...) when the V1 goes off abruptly! ;)

Re: Who Uses the "B" Setting on the Shift Lever??
 

Now that explains the confusion... ;)

Re: Who Uses the "B" Setting on the Shift Lever??
 

I read the Brake position is similar to 2nd and Low gear of a regular gas powered car. It said in the brake position is uses the generator to gear down till the traction battery reaches full charge. Then it switched to the engine and continues the gearing down. This may be when your at 45 mph and higher.

If the engine can't gear down enough then the computer gently applies the brakes trying to keep the car at a steady slower speed.

Re: Who Uses the "B" Setting on the Shift Lever??
 

I love B going down a long, steep grade!

I have used it on two trips through mountain ranges.

Re: Who Uses the "B" Setting on the Shift Lever??
 

No, seriously, B is meant specifically for when you've been going downhill so long that you max out the traction battery's SoC. Once that happens, B helps take some of the burden off of the friction brakes. It can also be used for added drag under less critical situations. Hope that's more clear than my last ramble...

Re: Who Uses the "B" Setting on the Shift Lever??
 

Short version - "Use B when going down a long steep grade - it helps keep your brakes from overheating and failing at the worst possible moment. Otherwise, don't worry about it." ;)