Entering Stage 4 - you actually don't need to be fully stopped.

Someone else (Hobbit, I think) mentioned it briefly somewhere along the line, but IIRC didn't quantify it like you have. And I've been unwilling to experiment and, in the process, risk losing 0.00275 MPG for the trip. Thanks for the info!

 

Just curious how can you tell your in stage 4?

 

I'm pretty sure I heard it from someone else, but it is true and
I also use the fact to creep along just fast enough to convince
someone behind me that I *am* moving until the "dance" completes
and I can take off normally. Really handy in morning stop-n-
crawl where deliberate distancing actually makes it harder to
come to a complete stop most of the time.
.
_H*

 

Wait a minute. If I leave my driveway still in the warm up cycle, and drive for 50 miles, never going below 10 MPH, does that mean I never got into S4?

There must be some other conditions, because I regularly get into S4 shortly after engine temp passes 152 F. Evidenced by RPM 0 IGN 5 on ScanGuage as I P&G.

 

You don't have to be in S4 for the ICE to shut down, as long as your speed is between 34-40 MPH. For it to be in S4 and, therefore, also shut down at lower speeds, requires the so-called "idle check" first: coming to a complete stop -- er, make that nearly complete, as Bob has documented -- for ~7 seconds.

 

But . . . to Doc Willie's point . . .

Does it really matter whether you've hit Stage 4 when you get up to highway speed and travel at 50+ for a long stretch of time? Is there any real benefit in getting there at that point?

 

It will go into stage 4 while constantly driving but might take a tad longer to do so. I've been on long drives without stopping and noticed it in stage 4 when I back off the pedal and get it into elec propulsion. In the morning headed to work, if traffic doesn't permit a stop a few miles down the road, I've noticed I can get stage 4 about 5-8 miles down the road as opposed to 2 miles if I make a stop. Go figure.

 

Thanks for the added info. Still, would it matter whether you hit Stage 4 so long as you are travelling at highway speeds the whole time? I've hit the so-called "Warp Stealth" or "Super Stealth" at speeds greater than 41mph, but it seems to be quite a freakish thing and not something I would be aiming for at 55+. Is there any other benefit to being in Stage 4 at high speed?

 

I can confirm it since I have done it before too. I found the ICE start easier after the shutdown. It seems as the battery discharge threshold is lower than the "stop S4".

 

My scan gauge shows my engine shuts down when my foot is off the accelerator just 100 metres after leaving my home. My speed would be under 30km/h. Do Aussie Prius behave differently? I'll pay more attention to the coolant temperature tomorrow.

 

Yes. I guess that's what is happening, and what I wanted to know.

 

My experience is the same.

 

Hmm, newbie here. What's this stage 3 - stage 4 stuff. Sounds really interesting. Any stickie I've missed?

 

http://techno-fandom.org/~hobbit/cars/five-stages.txt