Questions driving in the mountains

Exactly. I used the Power mode on climbs and used the B for braking going down long grades. This saves on the brakes not letting them get over heated. Heat causes premature brake pad wear and can warp the brake rotors.

 

I agree with the procedure Maurices uses.

 

The power mode doesn't give you any more power. It just determines how far you have to press the accelerator to get the desired power. So it may "feel" better but that's about all. B mode going down is good once the battery is charged however if you had a PiP it would be a whole different story

 

I still feel the car is much quicker in the power mode. The damn thing is quick off the line as well. I cannot make it fast in eco, it's a dog!!!. H

 

Yes, it may feel better. However there are lots of threads where it is made clear that all the Power Mode does is remap the accelerator profile so less push gives more acceleration but full push is the same. Or there could be a problem with your Prius.

 

It's funny how remap of the peddle makes it so slow. I guess my legs are not long enough. Damn thing almost feels like a sports car in power mode. Guess I will have to dig the stop watch up. I bet it will be slower in the quarter mile. Has it been tested at the track? H

 

I found out that when driving in the mountains that on downgrades as soon as the battery SOC reached 80% the engine braking would kick in automatically without me having to select B mode with the shifter.

 

Mine does this as well. My gen 2 does not do this ever. H

 

Correct, B mode just allows keeping the friction brakes cooler before the battery fills. I recommend it on any descent over 600 feet tall. (2500 feet in a PIP)

B mode just allows you to know in advance you are going down a big hill, the computer only learns it once the battery 'fills'.

 

It does make it quicker off the line.

 

Jimbo, I agree. I was playing around with trying to control vehicle speed on downgrades. Of course until the battery fills at 80% the regen braking will do a good job of maintaining speed. Engine braking cannot control the speed on long or steep downgrades so you will have to use friction braking at some point.

I have not done enough mountain driving to determine the best combinations but will be interested in other's observations.

 

What friction brakes In the PiP when I did the maximum regeneration of 150 Wh per minute for 4 minutes using modest braking at around 50 mph the friction brakes never came on. I don't see how the altitude change in feet would make any difference at all until the battery is full. The percent grade is a different matter. If you need to go slower because the maximum regeneration rate doesn't hold you back enough, then friction braking is needed. Except (?) the ICE would do braking first.

 

When you are going down a hill you can tell if you are "riding" your brakes and before or when you reach that point, put it in B mode.

 

Not in the PiP. Its appropriately "riding" the brakes that charges the battery and gives you those free miles for later use.

 

I don't have a PIP so I am totally ignorant as to how they work so I know you are right on your comments.

 

I did mention it took a LOT taller hill. If we could ignore rolling resistance and air resistance, and we can't, then for a given height, all slope angles have the same potential energy. Potential energy - Wikipedia, the free encyclopedia

 

Sorry guys, I did not realize this conversation was about PIP's. I should not have made any comments. I'm out of here

 

Its the slope (grade percentage) that requires the brakes. If the slope is steep enough friction brakes may be required in addition to regeneration braking (adsorbing potential energy) and ICE braking. If the altitude change is greater than required to charge the battery (more potential energy than can be used) then we just have ICE braking and friction braking. At that point ICE braking may, or may not, be sufficient depending on the grade percentage.

Section 3-5 Potential Energy, Physics for Science and Engineering Students, The Blakiston Company, 1952

 

Okinawa,

The OP has a Gen III, I have a Gen III and this thread is in the Gen III forum so do not feel bad. We just have some PiP users adding input to the conversation