What is the "B" on the gear shift joy stick?

I know what the B is I also try it out a few times it is just like a engine brake on a big rig / when you have a hard time of slowing down on ice or snowing roads or on a down hill just shift it into B and let up on the Gas Pedal and it will slow it down slowly but don't use it all the time it will decrease your MPG , any more ?'s about just let me know my name is Robert.

 

B mode is engine braking; using the compression of the gas engine to slow the car down, much like a 'Jake brake' on large trucks. I hunch most people don't find it all that useful, but the intent is to slow the car on long descents.

 

Don't use it in snow, it is better when a vehicle has ABS to use the brakes. Use it on very long down hill where you would otherwise need to ride the brakes but the battery would over charge if you didn't use B.
You could have searched for B mode with the search function, it turns up a lot of information.

 

It is in my '05 manual, which is probably identical to the '04.

 

It's in my 04 manual but I'm an Aussie.
It isn't a Jacobs brake but like downshifting in a conventional auto. You dump energy through the engine instead of the brakes. There is only an affect when your foot is off the accelerator.

 

See p.137 of the 2004 US manual. It does not describe when or why one should use "B". The only time it should be used is to avoid riding the brakes on a long downhill. Riding the brakes can cause them to overheat.

As a former resident of Wisconsin and Minnesota I can confidently state that there is no place in the midwest where one ever needs to use "B". The Black Hills, Appalachia, the Rocky Mountains, yes. I would not use it on snow or ice; the effect is like an immediate moderate application of brakes as soon as you take your foot off the gas, which is often a bad idea on a slippery surface.

 

As a Taxi driver i find the use of "B" mode very useful for slowing down more so when i have 4 adult passengers onboard,i know it dumps energy through the engine and uses a bit more fuel but i'll take that,working at night in Dublin city,there's always some gobshite who'll walk out in front of you and a bit of extra stopping power doesn't go amiss!!

 

It is similar to a jake brake in that it uses pumping losses in the engine to burn off excess energy. It differs as explained above in that it uses the electric motors to do this. Yes, it works in both gas and electric modes (technically it's a bit more complicated, because the gas engine will be spinning without gasoline, which could be considered electric mode.)

Tom

 

Look at page 140.

 

Also on page 15 of the pocket reference guide.

 

If you have experience driving a conventional automobile, then you may know that when you are descending a long hill it helps to shift into second gear or low gear so that your brakes do not work so hard to slow the car. B serves the same purpose as downshifting a conventional automobile's transmission.

 

I'd use it if I needed the brakes for more than about 30 seconds continuously, or more than 50% of the time over one or more minutes. If the brakes start to fade or smell bad then it is overdue.

 

I've yet to cook the brakes on the Prius, which is great. In our last car, I inevitably warped a disk nearly every camping trip, coming down the mountain passes. I'm definitely a convert to B mode and resistance braking.

 

A service manager claimed that if I didn't use B mode on the downhill from 1 mountain pass, I wouldn't make it up the next one with any speed here in the Rocky Mountains of Colorado. Any truth to that???

 

Not really. He may have meant that you wouldn't make it because your brakes would overheat and fail, but that would be a very indirect way of saying it. Use "B" to avoid riding and overheating the brakes.

 

it is a Braking system using the generator.
same as when you put on your brakes, but not as such a drastic slow down..