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

B mode wastes energy, use it if you can see your battery will be at full charge before you get to the bottom of the hill. It won't help you get up the next hill.

Search for B mode on Prius Chat and have a look in the beginners threads also, there is a stack of information, most good some not so good, go with the consensus and common sense.

 

The petrol heads (gearheads in USA) will tell you the Prius is a car designed to get you from A to B. Select B when you want the auto pilot to take you from A to B.

 

Very impressive on Google maps too. Search N45.589375, W118.631072 Never saw one like that on an interstate before.

 

Going uphill, you consume a LOT of gas going 10 miles! Going downhill I 'got' to see a truck use a 'runaway' ramp, they throw a LOT of gravel into the air!

Whenever I see a comment on when would you use B mode, I think of Cabbage Hill, Siskiyou Summit, and Grapevine.

Interstate 84 (west) - Wikipedia, the free encyclopedia
[ame=http://en.wikipedia.org/wiki/Siskiyou_Summit]Siskiyou Summit - Wikipedia, the free encyclopedia[/ame]
[ame=http://en.wikipedia.org/wiki/Tejon_Pass]Tejon Pass - Wikipedia, the free encyclopedia[/ame]

 

I've looked at those runaway ramps with horror. I can't imagine how scary that would be.

Tom

 

A couple of months ago a car hauler was going down Angeles Crest Highway, lost his brakes, and if the City of LaCanada had not planted oleandar and other weeds in the runaway ramps, thus rendering them USELESS, he would have been able to stop safely. Instead with no out or other stopping option, he rolled thru Foothill Blvd KILLING 2 poor souls who were in the wrong palce at the wrong time!!! Now he sits in jail, and the city council who approved the planting in the Runaway beds just sat there saying what a shame. It's not our fault.
Today the Runaway beds have been cleaned out and are operational again. Sadly they have banned semi's on Angeles Crest Highway.

It's sort of like closing the barn door after the stock has run away. Nice effort, but completly useless!!

 

How could any city get away with that? It's a state highway.

If California is so broke they can't even do inspections and highway maintenance then it's long past time to repeal Prop 13.

 

No, it's a braking system using the *engine*, which the normal brakes do not do, and it wastes energy. It should be used only when going a very long downgrade to avoid overheating the normal brakes.

 

I think, but I'm not sure, that it's a bit smarter than that. If your traction battery isn't well into the green, it regeneratively brakes more when you take your foot off all the pedals. When the battery is full, it goes to engine braking and throws energy away... a way to throw energy away when you can't store it, have too much to dump into heat in the friction brakes, but still need to slow down... like you said... long downhills.

 

B mode does do a little more aggressive regeneration, but it also immediately starts engine braking. B mode is throwing away energy right from the start. Your description is closer to normal mode, where regeneration is done up to the high limit on the battery, and then engine braking kicks in.

Tom

 

OK... I knew it regenerated on coasting more, but wasn't sure if engine braking started right away.... silly to use it until the battery's full then.

 

BTW... there are no hills worth using it anywhere near me.... it's going to be for use only during road trip holidays far from home.