What are the little cars on the MFD display?

Part of the way the Prius charges the traction battery is by regenerative braking, whereby the large electric motor is used as a generator, which results in the momentum of the car being used to recharge the large battery, thus slowing the car down without wasting the heat of brake pads rubbing on rotors (which does eventually happen below 7 MPH or so).

Each car you see on the MFD shows a specific amount of electricity (50 Wh) generated in this way, so you can see how much of your charging came from regeneration. A half-car would be 25 Wh.

 

darn i thought it was a video game?!:fencing:

 

Four of those cars is about enough energy to accelerate the car once from zero to 60 MPH.

It may sound like a paradox, but for best fuel economy you want to *minimize* the number of little cars you get, that is, minimize the use of the battery. Energy conversions such as moving energy into and out of a battery always result in some energy lost as heat.

How do you minimize use of the battery?
- Accelerate briskly (this uses the engine most efficiently)
- Gliding (no arrows on the energy display) is better than coasting
- Coasting is better than braking
- Braking is better than stopping
- And of course, Stopping is better than hitting something :_>

 

no way, 50 thousand watts/hour? that would light my house for a month

 

When you buy electricity they charge you by the kilowatt-hour (kWh). When you use a 1 kilowatt appliance for 1 hour, that's a kilowatt-hour. If you used it for two hours that would be 2 kWh.
Most things don't draw an even kilowatt, though. A typical central AC draws about 3.5 kilowatts, so in an hour it uses 3.5 kilowatt-hours. And a 100-watt light bulb uses 0.1 kW, since 1000 watts = 1 kilowatt.

 

Couple other trivial points:

1) the less 'little-cars' you produce, the more efficient you are driving. Since the cars represent regen, remember its more efficient to be using that energy to the wheels rather than feeding it back into the batteries.

2) Other models use different icons, rather than little cars. On our lexus SUV hybrid, the regen icons are little batteries.

 

dude, i know this, i have an ee degree...i was being a little sarcastic to his mistake of each car being 50 thousand w/hr, what he meant was 50 w/hr's

 

Maybe I can enlist your help on my car PC project in the near future!

 

When I first read the legend on our consumption display, I misread it as each car being equal to 50 kw-h. I saw that and said "holy shit", then I realized my mistake. It's still better than making heat. If it was up to me, I'd display the little green cars in ergs, just to mess with people. The cgs system just doesn't get any respect.

Tom

 

richard schumacher that made laugh all day...i needed that!!
:rofl: And of course, Stopping is better than hitting something :_>

 

My green car represents 5000uW/hr!!!

 

Glad to be of service :_>