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Discussion Starter · #1 ·
Can someone explain to a female newbie (2 1/2 months) Prius owner what the bar graph with the car symbols mean? I've read the manual but I'm not a techie type and I have no clue what they're talking about. :oops: Thanks.
 

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janets98 said:
Can someone explain to a female newbie (2 1/2 months) Prius owner what the bar graph with the car symbols mean? I've read the manual but I'm not a techie type and I have no clue what they're talking about. :oops: Thanks.
2.5 months to ask...and they say men will never ask for direction(s)!

It's OK, it's kind of an odd graph. Every 5 minutes a bar pops up. The bar shows your average mpg for that 5 minute time period. That can be pretty useful when you're traveling at a set speed. It can also be pretty confusing and meaningless if you're in stop and go traffic. For instance, if you drive 100 yards during a given 5 minute period then stop completely that 5 minute bar may show an abysmal mpg...maybe 10-15mpg b/c the amount of fuel used vs the distance traveled, divided by the amount of time will be low.

But if you continue to sit, not moving at all, for the next 9 minutes, your second bar will show 100mpg, even though you haven't moved an inch!

The real value of the bars is to show you how you're performing over a given period of time during a given trip. Lots of high bars with few regen car-leafs is good. Lots of low bars with lots of car-leafs is bad.
 

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Discussion Starter · #3 ·
Thanks, efusco. I know. I'm so bad not to have sought help before. :oops:

I can easily follow your explanation of the mpg in 5 minute increments but what the *&$# are "regen car-leafs"? :? And what do I do with them? :?
 

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They're there to tell you how much energy you've regenerated. One leaf is 50Wh. It just shows how much braking you've done I guess. I can't remember if engine recharge shows up as leaves.
 

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Discussion Starter · #6 ·
Ok, now I see that the car symbols are 50 watt hour increments. But I don't understand whether or not they're a good or bad thing. I thought the fact that unused energy was returned to the system was a good thing. Now I'm reading that too many of them are not a good thing. Is this because it means that the speed is not being kept steady? That I'm using the brake too much? If they're a bad thing, how many car symbols are too many? :?:
 

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My understanding is that the car leafs represent the amount of energy from regeneration, which could be from braking or slowing down (whenever the display shows energy going from the wheels through the electric motor into the battery). I believe it was intended to be seen as a good thing on the display (else why would it look 'green'). I don't think there's much you would want to do to control it, other than to slow down more gradually when you can because if you brake too hard, it has to use the brake pads in which case not as much of the energy is recovered.
 

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If you had no choice but to brake, then those cars are good, because that means SOME of your energy after stopping was returned to the battery, instead of being converted to heat from the brake pads.
But if you do lots of driving right to the light and suddenly braking, instead of spending some of that time coasting down to stopping speed, then the cars are a waste.
There is always loss in converting energy from one form to another.

I have to disagree with you Evan, if you don't drive at least one inch (maybe a foot to be detected), then you have 0/(anything but 0) which is 0, and it WILL show 0 on the 04/05. However, it is my understanding that the classic interprets 0/0 as infinite. Doesn't matter, 0/0 is undefined mathematically.
If you drive 1 foot, .0001/(anything including 0) can show anything from very low MPG to very high. In other words, if you closed the gap between you and the car in front of you at a stop without ICE starting in the last 5 minutes (EV/stealth), you have .00001/0 which on an '04/'05 is shown as infinity.
 

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If you look toward the top of the consumption screen you will see a little green car and = 50 wh regenerated. That is your key to the green cars. Sometimes a half a car will show up, indicating 25 wh. I'm not sure how accurate that is, but it is more representational than nothing at all.

Anyway, I've heard it said, and I support this, that the green cars just exist. They are neither good nor bad. It is the car's way of demonstrating to you that it is regenerating when you slow or brake, and it corresponds that slowing or braking to the 5 minute interval it is displaying.

There is always conversion loss, as others have stated when you take one form of energy, in this instance kinetic energy associated with the momentum of the vehicle you are trying to stop and turning it into electrical energy. However, it is better to have collected this energy in the form of electricity rather than just to the brakes.
 
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