[Oh4Prius]

I am curious how others use "B" mode on the drive shifter...
Do you ever use B mode?
If so: do you use it for going downhill?
do you use it to help you slow down quickly from freeway speed?
do you use it in any other way?

 

[wayneswhirld]

I use B mode whenever I commute to work since I go over a mountain. It helps slow the car down going downhill as if you downshifted. This saves brake wear. However, keep in mind that when you go downhill in B mode, you can only stay in it for a few minutes until the main battery is fully charged (all green bars filled in on the Energy MFD). Otherwise, you'll find the motor revving or spinning fairly high in an effort not to overcharge the battery. At this point, just shift back to D.

I also occasionally use B to slow the car down as I am approaching a red traffic light or turn.

 

[DanMan32]

Otherwise, you'll find the motor revving or spinning fairly high in an effort not to overcharge the battery. At this point, just shift back to D.

But that's just the point of using B.

 

[richard schumacher]

I use B mode whenever I commute to work since I go over a mountain. It helps slow the car down going downhill as if you downshifted. This saves brake wear.

So far, so good.

However, keep in mind that when you go downhill in B mode, you can only stay in it for a few minutes until the main battery is fully charged (all green bars filled in on the Energy MFD). Otherwise, you'll find the motor revving or spinning fairly high in an effort not to overcharge the battery.

Uhh, that's exactly what it's supposed to do. If you shift back to "D" before you get to the bottom of the hill you will resume wearing out your friction brakes pointlessly.

 

[alsgameroom]

I use B Mode sparingly but moreso when I know I am not going to be able to recapture kinetic energy, typically this means coming to a stop or going down a hill where I will end up exceeding a safe speed.

there is one hill near me which will easily overcharge the battery and causes the big motor to spin loudly. I have timed this hill so now with about 7 bars I begin descent at about 35 mph and put her into B mode when I reach 45 mph.

Its just coincidental that the road after the hill is such that I can cruise pretty far in EV. :lol:

 

[coloradospringsprius]

We use B mode about once a month when going down mountain passes. In town, we've used it only on one long, steep hill. A light foot on the brake is usually a better way to slow down. It gives you back some electricity and does NOT engage the brake pads.

 

[KTPhil]

I use it in only two cases:

1) I am going downhill, a little over the limit, a cop is/may be up ahead, and I want to slow down without the telltale brake lights, thus making the cop pull over the guy driving next to me, who hit his brakes and looks more guilty than I do. The cop assumes his radar gun locked onto the other guy, not me. In other cars I'd use the e-brake handle, but the push-to-release Prius e-brake prevents this tactic. Ergo, B-mode instead.

2) I'm in 10-20 mph slow'n-go traffic on the freeway, and my right calf is tired of brake/gas/brake/gas exercises. I just let up on the gas and I slow down enough to not have to hit the brakes. Some in Japan have claimed a higher regen under these narrow conditions, too, but it's for my comfort, not my mpg. Lack of brake lights isn't a problem as some say, since this behavior is exactly like a stick shift car.

 

[Whatsthat]

I use it to slow down comming off ramps when my battery is low. In our town we have 4 interstate onramps/exits within 2 miles. I use it going to work which is only 10 miles from my home. I use EV as much as possible on my route to the interstate and recharge with the B mode and the breaking in general.

 

[wayneswhirld]

However, keep in mind that when you go downhill in B mode, you can only stay in it for a few minutes until the main battery is fully charged (all green bars filled in on the Energy MFD). Otherwise, you'll find the motor revving or spinning fairly high in an effort not to overcharge the battery.

Uhh, that's exactly what it's supposed to do. If you shift back to "D" before you get to the bottom of the hill you will resume wearing out your friction brakes pointlessly.[/quote]



I am nervous about leaving it in B when all of a sudden I hear the loud revving/spinning sound. Even Toyota service advised me to shift to D once the battery is fully charged. I'm 3/4 down the hill at that point, and not as steep anyway.

 

[richard schumacher]

I am nervous about leaving it in B when all of a sudden I hear the loud revving/spinning sound. Even Toyota service advised me to shift to D once the battery is fully charged.

Toyota, or some dealer's employee? I'll bet the latter; they were mistaken.

 

[coloradospringsprius]

I use it to slow down comming off ramps when my battery is low. In our town we have 4 interstate onramps/exits within 2 miles. I use it going to work which is only 10 miles from my home. I use EV as much as possible on my route to the interstate and recharge with the B mode and the breaking in general.

Except that you recharge less in B mode than in D.

 

[DanMan32]

I suppose the amount of charge received in B before it hits 'full' will only be determined by a scanner. Atilla, want to check on this?

My hunch is that B increases the default regenerative drag, so you don't have to put your foot on the brake as much. So if you are just getting off a highway ramp, that's only a short distance, so use the brake pedal, as I believe you accomplish the same thing.

 

[hyperion]

I would completely ignore it for main battery charge. The Prius will take care of itself. Indications on the MFD I believe are not meant to change your way of driving. I would use the "B" mode at anytime I see the sign for 18 wheelers to downshift account of steep grade. They to protect their brakes from overheating and ditto for the Prius. Otherwise I would ignore it being in the car.