Hybrid System Indicator and Stealth

[DaveinOlyWA]

Stealth is a term to describe "no arrrow" mode in the classics which means that the power flow is not predominately going in either direction as far as motor, engine or battery...(obviously there is flow out of the battery since SOC does go down)

when Stealthing you will experience a deceleration rate of 1mph per every 3-6 seconds or so and is probably the best method towards achieving the very high mileage numbers so this mode is the best way to use a stored charge

well today (being Tuesday and my weekly "errand" day) i had a chance to do a bit of cruising using the back city roads which is great for hypermiling due to minimal lights and the 35-40 mph speed limits plus the usual "middle of the week in the middle of the morning" light traffic.

on the HSI screen, i noticed that when i am Stealthing (i think since its much harder to determine or feel it than the SPM which i could do without looking at the screen) the indicator is simply all over the place which i would assume is giving me a much better feedback as to what the car is doing in deadband mode.

interested in anyone elses thoughts on where on the HSI should we be to better keep in Stealth mode?

[efusco]

Hey Dave, just to keep the terminology consistant, we used the term "deadband" to indicate the condition where the engine (ICE) is running with arrows on the 2G Energy screen going to the MG and to the wheels but no arrows going to or coming from the battery.

We used "Stealth" to indicate the no arrows at all condition of gliding.

[a priori]

I've been trying to figure that out myself. The car is just too quiet and the HSD is too smooth. Either that, or I just haven't been able to get accustomed to it yet.

I had relied for awhile on the Gen2 Energy Screen for the feedback I needed, until I got to the point of really feeling my way through it.

I don't really like the similar screen in the 2010. It is small, the "car" is aligned differently, and there isn't much color -- the feedback is just not the same. It may be no issue for those who didn't have the earlier model Prius, but I just am not ready to adjust to that screen. I've also defaulted to the HSI.

I cannot for the life of me figure out exactly what that screen is supposed to do. I get the "Charge" end of things and the red "Power" end -- pretty big clues as to what is going on. I'd like to know why there is a vertical line in the center of the screen. Anybody? Bueller?

I think the closest I come to deadbanding is getting that HSI screen clear of anything on the charge side, while also keeping the indicator to the left of the vertical line. The MPG indicator suddenly spiking also is a good clue!

[DaveinOlyWA]

oh ya... you right...hold on.... ok, can you change title of thread?

[DaveinOlyWA]

Originally Posted by a priori

I've been trying to figure that out myself. The car is just too quiet and the HSD is too smooth. Either that, or I just haven't been able to get accustomed to it yet.

ya!@! i know what you mean. on my SPM you can feel the motor running...on the 2010, i have to have everything turned off most of the time to "hear" the motor running and rarely am i able to determine when it comes on and off.

also on the 2010, i maybe getting old (ok, well i am old!) but the red is very tough for me to see especially at a glance so i dont use that screen at all any more besides the HSI is new so it has my attention for now, but wish i could see it and the old energy screen at the same time.

one thing i noticed though. the areas of regen and the charge band (not so much the power band) dont seem to be exclusive on any certain condition of the car unless its also tied in to what mode the car is in.

for example, even when i am in EV or glide mode, i have 100+ mpg but can actually get the indicator to nearly the power mode band....

same with when i am burning gas, i tried to see if the position of the charge band would correlate to my MPG reading and it varies widely even after warm up.

so i am thinking the Pri modes are

gas to engine+ charge to battery+ power to wheels from motor
gas to engine + charge to battery+ regen
gas to engine + power to wheels from motor
gas to engine+ charge to battery

which then controls what the HSI shows us

hmmm... anyone catch what i am trying to get at?? if so, let me know cause now i am confused

oh ya... my center area has a line with a distinct difference in the shade pattern as well

[Philosophe]

Originally Posted by a priori

I'd like to know why there is a vertical line in the center of the screen. Anybody?

I'm not sure but what I understand from my different readings is that the line represent the point where the engine starts/stops to assist the electric motor...

[DaveinOlyWA]

Originally Posted by Philosophe

I'm not sure but what I understand from my different readings is that the line represent the point where the engine starts/stops to assist the electric motor...

hmmm nope... at least not always. like i said, i have been in stealth mode and reached nearly to "power" band

[Jay C]

here is what I figured out, and if I can find it again, I'll post the link tot he 20201 Hypermiler review.

Once the engine is heated enough to shut down the ICE, any amount of bar on the left of the center line = electric only. If the bar is in the charge then you are regen ... if you hold the accelerator so that it's not charging and not electric, you are in "glide" or deadband.
Once you pass the center divider the ICE kicks on. To turn it off, let off the accelerator until the bar falls below 30% on the electric side (if it doesn't kick off, then it's charging the battery). As far as when you are using the ICE and recharging the battery, I haven't figured out how to tell on this screen and have to push the Info button 5 times to get the the car display

FWIW,
Jay

[Jay C]

Found it: 2010 Prius Preview: A Hypermiler's perspective

[DaveinOlyWA]

Originally Posted by Jay C

Found it: 2010 Prius Preview: A Hypermiler's perspective

nice article and it does provide some insight (no pun intended) to the HSI display, but his experiences simply dont match mine.

i dont see any guaranteed indicator in any specific mode.