Little green cars? Meaning?

If you look above the graph it tells you exactly how much each "car" is worth. The cars are used to represent energy captured during regenerative braking. this is essentially "free" energy that can be used to move the car but doesn't cost you anything.

They only show up "sometimes" and in different quantities because not every 5 minute window of driving is the same. if you're just cruising down the highway with minimal traffic, odds are you won't see them. If, on the other hand, you're driving down a busy street with lots of stop and go, traffic lights, etc. odds are you'll see a lot of them.

People on the site here view these icons as both good and bad - good, because it's energy that would have otherwise been lost, and bad because it means you maybe weren't driving as "optimally" as possible. Every time you accelerate quickly only to have to brake to stop is a waste of gas - the ideal is to accelerate to exactly whats needed so you can glide down to a speed where you don't have to stop at the light. of course, with traffic you have to make compromises, because this type of driving can be dangerous if those around you aren't expecting it.

 

<div class='quotetop'>QUOTE(gene4655 @ Nov 3 2006, 12:02 PM) [snapback]343458[/snapback]</div>

They indicate that the braking and/or coasting of your car is generating electricity which is directed back into the traction battery for later use by the car. I am sure others will chime in with more details.

 

Hi Geno, you have a fairly common question. I think the answer may be right there on the Consumption screen. The vertical bars represent your fuel efficiency over five-minute intervals; the little leaf-cars (look closely and you can see the leaf veins, this is an environmentally sensitive car) represent regenerative braking input to your battery. Each little leaf-car represents 50 watt-hours of energy that went into your battery for re-use by the HSD, rather than be turned into heat by friction brakes in a conventional car.

You shouldn't try to get the little leaf-cars. While they represent energy re-captured, the ideal would be to not ever have any excess energy. You can't drive without stepping on the brakes, but the less you can use your brakes, safely, of course, the more fuel efficient your driving will be.

 

Yea ... regen blips. 50kw per hour. Our Lexus SUV hybrid only has little green squares. My 1st thought about that was, "HEY! ! ... where's my little green cars?! ". I kinda like the cars better in our Prius.

 

<div class='quotetop'>QUOTE(Tideland Prius @ Nov 4 2006, 02:10 PM) [snapback]343808[/snapback]</div>

Well, I'll check when my wife gets home, but no, I'm pretty sure they are dumb little green rectangles (tho I called them squares above).

 

<div class='quotetop'>QUOTE(hill @ Nov 4 2006, 10:02 AM) [snapback]343801[/snapback]</div>

Each green car represents 50 Watt Hours (not kw per hour). That is enough energy to drive the Prius about 1/4 of a mile.

kevin

 

Today while coming home in stop-and-go mostly downhill traffic, I had one bar that was almost at the top AND three green cars in it!

Don't ask me what my mileage was going there, though...

 

[attachmentid=5620]<div class='quotetop'>QUOTE(Tideland Prius @ Nov 5 2006, 02:36 PM) [snapback]344144[/snapback]</div>

Alright sure. Guess you didn't drive OUR RXh ~ be it 05, 06 or 07. Maybe I'm color blind and flunked geometry :^)

what do you think about those yellow diamonds.

 

Those look more like little batteries than rectangles - but definitely not as cool as on the Prius!

 

<div class='quotetop'>QUOTE(eagle33199 @ Nov 7 2006, 10:39 AM) [snapback]344931[/snapback]</div>

Yea! Batteies! Heck I'm so far sighted, I couldn't even see there was an 'E' in the Center 'till viewed through the camera ... much less the little positive terminal bump. Maybe when toyota / lexus finally come out with production plug in hybrids, they'll switch icons again ... how 'bout little 50K volt power poles?!?

 

A while back someone posted a sheet analyzing some specifics of the Prius. The sheet stated about 260 Watts is needed to move the car about a mile at normal highway conditions. So about 5 green leafs or so gets you a "free" mile compared to a conventional vehicle. It also stated the Prius is only about 30% efficient in capturing braking energy. Maybe through the use of ultra capacitors that figure could be improved in the future. A green leaf was equivalent to about a tablespoon (1/2 oz) of gas. Not a lot but every little bit helps.

But another factor I consider to be a big plus for regenerative braking is less use of the conventional brakes. I do not think I will ever need to replace the brake pads on my Prius for as long as I own the vehicle. Even in fairly heavy stop and go conditions sometimes the brakes are still only warm to the touch, if that. Try putting your fingers on the disk/drums of a conventional vehicle after a bout of stop and go conditions...

Remember, ALL power from your Prius ultimately comes from the ICE (Internal Combustion Engine). Under most, but not all conditions, it is more efficient for the power from the ICE to go directly to the wheels. Anytime you generate and use electricity, you are introducing power loses to the system. But the ICE is not running at its best efficiency for all speeds you may typically travel and the computer may decide that the loses from electric alone (sometimes below 42 MPH) are worth the trade off from running the ICE.

Bottom line is, unless you are pulsing and gliding (I'm too lazy for that...), just let the computer figure out when to use the ICE or motor. I get very close to the EPA numbers, drive with the flow of the traffic, and nearly always have the A/C on.


Rick
#4 2006

 

I too am a new Prius owner (got my '07 on Saturday). I understand the little grean cars, but I still really don't understand how that chart is working or what it's fully telling me. It's obviously measuring recaputured energy for segments of the drive (first five minutes, next five minutes, and so on). But I don't understand what the height of the yellow bars mean. I can't seem to see a relationship between the height of the bars and the green cars. Are the bars average mpg?

 

<div class='quotetop'>QUOTE(eej5 @ Nov 8 2006, 11:34 AM) [snapback]345458[/snapback]</div>

The little bars on the chart represent miles per gallon acheived during each 5 minute interval. For example, if you count the bars in the above pictures you will see there are 20 bars which directly across reads 20 mpg. Thus 30 40 50 bars would equal that many miles per gallon during that particular 5 minute increment.

 

http://priuschat.com/index.php?showtopic=18678&st=11 to gain some
additional insight into how much energy that is...
.
_H*