Three unrelated questions

[philmcneal]

<div class='quotetop'>QUOTE(orenf @ Oct 5 2007, 02:31 PM) [snapback]521947[/snapback]</div>

Hi,

Here are three unrelated questions - answers/comments are welcome.

1. The gas engine is variable/continuous - the harder you push the pedal, the more power you generate. Does the electric engine work the same way, or is it a simple on/off discrete mode, and it does not matter how hard/fast I push the pedal (within the applicable speed limit for the electric engine)?

2. I've read several times that when gliding at high speeds the MFD does not show any energy flow, but the gas engine is "spinning" - what exactly does it mean? Is fuel being consumed or not? the MPG is always at 99 when gliding.
Is this the equivalent of taking your foot off your non-hybrid's gas pedal (have no idea what actually happens then)?

3. I was recently stuck in a traffic jam off hwy 1 near Vancouver. Other than being stuck in traffic, it was not that bad - music was playing ,car was not consuming any gas for several miles, the perfect hybrid experience.

Next to me was a Civic hybrid - can anyone tell me what happens in a Civic hybrid - I understand there is no EV, does that mean that in a traffic jam the only benefit is the engine cut-off when stopped, but otherwise, while plodding along at 5-10 MPH, it consumes gasoline just like any other car?

That's all for now...

--- Oren
[/b]

questions 1 and 2 can be answered by http://www.cleanmpg.com/forums/showthread.php?t=1224 and questions 3 http://www.cleanmpg.com/forums/showthread.php?t=1306

[darelldd]

<div class='quotetop'>QUOTE(9G-man @ Oct 6 2007, 03:26 PM) [snapback]522255[/snapback]</div>

I don't think question #1 really got answered.

Yes, The power output of the electric motor(s) is variable with accelerator pedal pressure, just as ICE power output is variable. The electric portion is not just on/off when you step on the accelerator in electric mode.[/b]

Ah, you beat me to it. When you start off from a stop gently, you can clearly see that the "EV mode" has variable power output from the accelerator pedal. You can "drive" with battery only. If it were a toggle switch, it would be pretty uncomfortable to drive! Would be like lighting JATO units, on a little, tiny scale.

[9G-man]

QUOTE(9G-man @ Oct 6 2007, 03:26 PM)

I don't think question #1 really got answered.

Yes, The power output of the electric motor(s) is variable with accelerator pedal pressure, just as ICE power output is variable. The electric portion is not just on/off when you step on the accelerator in electric mode.[/b]

<div class='quotetop'>QUOTE(darelldd @ Oct 6 2007, 07:03 PM) [snapback]522270[/snapback]</div>

Ah, you beat me to it. When you start off from a stop gently, you can clearly see that the "EV mode" has variable power output from the accelerator pedal. You can "drive" with battery only. If it were a toggle switch, it would be pretty uncomfortable to drive! Would be like lighting JATO units, on a little, tiny scale.
[/b]

And if you get an EV switch you can really see that electric power is highly variable with accelerator pedal input

[David Beale]

1. The electric motors work the same as the gas one. The harder you press on the accelerator, the more electricity you use. They are electronically controlled three phase motor/generators. If you press hard enough, whether you are in "EV mode" or not, the engine will start. The reason is the system has to protect the battery. The electric motors can generate more power than the Prius uses, but the battery cannot deliver that much current safely (for battery life). So the engine is started to deliver some of the current being demanded and to provide direct propulsion as well.

2. The engine must spin when you go faster than 43 MPH/66 kmPH to avoid over-spinning MG1. It is spun up by MG2 to about 950 RPM, with no fuel being injected. Below the above speed it is allowed to stop.
If you take your foot off the accelerator the system goes to "engine braking simulation regeneration". That is, it regenerates enough to cause as much braking as the Toyota engineers thought an engine would under similar circumstances in a "normal" car.
To see this, use the flash program available in the sticky thread under Prius Technical:-
http://priuschat.com/Introduction-to-Prius...low-t30286.html
With this you can vary the engine speed, vehicle speed, etc. and see the effect on the various components.

3. I have no experience with the Civic Hybrid, but from reading the forums, the latest version should work very much like the Prius.