Rookie Question:"B" Drive

You will rarely use 'B' mode unless you are in a mountainous or high-incline area. It is similar to downshifting a normal car, as it uses engine braking to help slow the car. However, it is NOT a mode you would ever use in Minneapolis...

 

I have used 'B' three times all three coming down major passes in the Rockies and Cascades (briefly, they are not the Rockies). For smaller hills using D and braking lightly is a better strategy.

 

just want to know, will putting the gear into "B" will help the car charge the battery more?

does anyone know how to charge the battery to the max? I can never drive the car to charge it to the full ..... always one bar to go till the max

 

One time when it can come in very handy is in a near-emergency stop. I've had someone stop-dead in front of me on a major highway, for no obvious reason.

Whapped it down into B and stood on the break - was AMAZING how quickly the Pri managed to skid to a stop.

Perhaps I imagined it, but I don't think so.

On a related note I saw a sign in a tiny little Texas town on a county-highway (backroad) that stated clearly, presumably for truckers but I guess for those in the know it could have applied to me - NO ENGINE BRAKING IN CITY LIMITS.

First time I'd ever noticed such a sign.

Terry

 

After 25,000 km, I pretty much ignore the B mode. I used it quite a bit at first, thinking I was regenerating energy and using less gas, but I was wrong. I don't use it now even down the big hills, like the Rockies. Either I let the speed build to carry me up the next hill, or I use the brakes.

 

We have quite a bit of these signs around our community. These signs were put in place because most truck engine brakes are VERY loud and annoying. The Prius is a zero noise engine brake, so I wouldn't hesitate to use it in these zones.

 

Oh I used it, just to be rebellious.


Terry

 

I wonder how similar the Prius "engine brake" is to a truck's engine brake. My somewhat limited understanding is that a truck's engine brake is different because of the manor that a diesel engine works compared to a standard gasoline engine. Then again, you can't say that the Prius has a standard gasoline engine.

 

My understanding is that engine braking, whether gas or diesel, works by using the compression of the engine to slow the wheels.

The one time I have found the Prius' B mode helpful is in the snow. (Yes, snow tires would be a safer option, but they're hard to justify in a place that snows maybe twice a year.)

 

At my local dealership, I ran into a guy who is a trainer at Toyota's regional training center in Tucson. Matt Something-or-other. He was driving an '05 Prius and says he is known as "Mr. Prius" to other Toyota employees. The guy gave me a 10-minute tour of features I had never seen or heard of before. He told me the B setting does charge the battery, and if you tap B twice, it charges at a higher rate (and slows the car more).

I have used "B" on downhill slopes in the mountains (I'm in Colorado) and there is no doubt in my mind it charges the battery. Once the battery is on the top bar while in "B" mode, the engine makes a fairly loud revving sound until you take pop it back into "D". I now use B on off ramps and whenever I have to decelerate from a fairly high speed, like in rush hour or coming up to a light. Admittedly, I am playing a bit, but my battery indicator is usually pretty high. I'm just not sure what that gets me.

 

I have not seen anything about "tapping" B twice. Is there any source for this other than a comment? Any one with a Scanner that can confirm this in a G2 (classic) Prius?

 

I don't think anyone said that B eliminated regenerative charging, just that it doesen't enhance regenerative braking. Going down long hills turns the battery indicator green, B or D, but not N. N might as well mean N(o charging).

I've never heard of double-tap B either, but I don't believe what I'm told...

 

My point, supported by "Dr. Prius" (we need to get him on here), is that B does enhance the regeneration. If not, explain the revving sound while in B only when the battery becomes fully charged. B is described in the manual as "engine braking." So the question is whether engine braking adds to regenerative braking. It does.

Flatlanders may not have the benefit of mountain passes to test this for themselves. I observed it on the downsides of Slumgullion Pass, the Grand Mesa and other mountain drives in Colorado.

As for the double-tap, try it yourself. It has a more subtle effect than a single B tap, but it is noticeable. I can't confirm the additional enhancement to charging caused by a second tap.

 

The thing about the B mode I can't stand (but I admit it's my fault!) is that it's too easy to forget to get back into D. I am sure I'm not the only one, though. It really killed my MPG! I don't use it any more!