Hybrid System Indicator and Stealth

Am I the only one who can hardly see the red engine arrows? I also think they could have used larger and brighter letters throughout their indication system. I was an Air Force and airline pilot and I never ever had a hard time seeing any instrument in any plane I flew.

linkster

 

I will be referring to this thread's graph provided by Ken@Japan here: http://priuschat.com/forums/gen-iii...2010-prius-2zr-fxe-engine-efficiency-map.html

After some 4000 km on a trip (an old car it is now), here is my understanding of the Hybrid System Indicator. (I would really like to confirm this with a Prius engineer...) :
- 1.a. The CHG part represents the qty of energy being put back in the traction battery. The further left you go, the more goes to the battery. If you break harder and let the indicator go pass the left limit of CHG, you are probably generating more current that can be efficiently accepted by the battery, hence dissipating part of the current as heat somewhere in the inverter/traction battery.
- 1.b. The point between CHG and the middle part represents a neutral spot where neither MG1 or MG2 are putting/pulling power to/from the wheels.
- 2.a. The Central left part represents the most efficient use of the HSD. If the engine as no reason to run already (ie. engine is warmed, traction battery doesn't need to be charged, heater doesn't require the engine to provide heat) and when under ______ km/h (haven't found the exact speed yet), only the motor will provide traction. As soon as you cross the central line, the engine will always kick in. As the car gets faster than ______ km/h, the point where the engine kicks in will progressively shift left according with the car's speed. e.g. When going at 130 km/h, the engine will kick in almost as soon as you press the gas pedal to leave the neutral point to the right of CHG.
- 2.b. When releasing the gas pedal, the engine will stop at a speed that varies with the car's speed. Fully releasing the gas pedal will stop the engine unless the car is going at more than ______ km/h (arround 90-100 km/h, not sure yet).
- 3. The Central right part represents efficient use of the HSD, including the engine. Engine will run. Engine RPM will be kept low, in the most efficient use of gas (see reference, may be the long progressive slope between 500-3500RPM).
- 4. The PWR part represents a point where the engine RPM will go up and push the engine outside of its most efficient zone (may be the point arround 3500RPM in the reference). The further right, the less efficient it is.
- 5. I'm trying to understand what the PWR right-hand limit represent. When you cross that limit, I guess you are going into inefficiency, pushing the engine RPM without getting a lot of usefull additional torque (may be the point above 4000RPM).

Can someone with a ScanGauge confirm all this?

Also, I would like to understand if there is a big/small/insignificant MPG difference between using smooth accelerations (just pass the central line) and using brisk accelerations (staying bellow the PWR zone). I haven't tried the two on an established route to see the impact on MPG.

I also have different "engineering" questions as:

- The new cruise control will slow the car down when needed to keep its speed. Is this only a "driver's convenience" feature? Can it be possible that the innefficiency generated by drawing cinetic energy from the car to store it in the battery and later convert it back in cinetic energy be less than the innefficiency of letting the car go faster and faster down the hill, increasing aerodynamic drag to the car? The cruise control slowdown would then increase MPG! :shocked:

- Usually, EV can be used if the car goes under 40 km/h. Sometimes, I get kicked out of EV mode when the car cross 18 km/h, the screen clearly stating that I'm going at an excessive speed... I don't understand...

[EDIT: Ken@Japan have answered this in another thread: The limit is:

• 40km/h (25MPH) when the engine warmed

• 16 km/h (10 MPH) when the engine is still cold]

- Sometimes, the engine will start for no apparent reason when I start the car. (No, heater is not on, yes the battery is fully charged). I don't understand...

[EDIT: I seam to understand that the engine will always run when you start the car, to warm up the engine. You can manually prevent this buy entering EV mode quickly after hitting POWER (if the traction battery SOC is sufficient).]

Maybe we should start a thread dedicated to engineering questions for Toyota and that could end up in John1701a users guide...

 

No, I can barely see them as well. Not only that, I didn't even realize they were red until my 12-year-old daughter pointed it out. I don't think my eyesight is that bad.

 

Looks like the other thread I tried to start about this got buried
too fast for anyone to see. I'm looking for comments on the
content referenced therein, as I think it'll help explain a lot
about how the HSI works.
.
_H*