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View Full Version : stage between 2 and 3 in prius II?


locutus
03-05-2007, 12:46 PM
Hi all,

I've noticed something from watching scangauge output that I'm curious about.

In stage 2, either with NICE-on coasting or if I can get no-arrows (but still ICE-on) glide, the scangauge reports MPG almost exactly 3x MPH (so for example at 31MPH I'm seeing 93MPG on the nose), and an idle RPM around 1150.

Once I hit 145F WT, this same situation, though still in stage 2, now causes the scangauge to report exactly 5xMPH (so 31MPH now shows 155MPG), and an idle RPM of right around 1000.

What makes me curious is that this transition is sudden and always happens at 145F. Is there something going on between stages 2 and 3 when this transition is crossed? I haven't noticed any implication from this for being able to drop into forced-EV or anything else that might be able to be manipulated for MPG gain...yet. ;)

brick
03-05-2007, 01:44 PM
Best guess, 145F is the point at which the ECU decides that the engine is warm enough to operate nominally and stops burning extra fuel to get warmer faster. That's all a faster idle does as far as I'm aware.

philmcneal
03-05-2007, 03:05 PM
145F is 50 degrees C right?

on the classic prius I know the "cold engine" light turns off at 50C so like brick says... less fuel to climb the temperature.

i still *HATE* the transition from S3 to S4 and sometimes when the prius likes to be a pain in a butt, it likes to jump back to S3 which forces me to either

A) stop completely and maybe piss off someone behind me

b) exceed speed limits of 55km/h or 64km/h depending on how garbage the prius is acting

only by doing one of those two rules where i can get the engine to be killed when letting my foot off the gas... i can understand why some prefer 5spds to hypermile if their commute isn't all jammed up on a daily basis.

More to come... if you haven't noticed brick... i drive your car now ;) but with CAN VIEW installed hehe...

brick
03-05-2007, 04:31 PM
Ha! Wow, Phil. As an old boss of mine once said, "You go through cars faster than you go through shoes!" Nice choice!

On my commute I never get out of S3. It's not so bad since the limits around here are 35mph (precisely the speed I have to reach for the car to stealth) but there are a few locations (precisely five) where 35mph is too high of a target. In some of those cases the EV switch does the trick. Back off the accelerator, tug on the cruise control stalk for three seconds, and you're gliding. It's just like a FAS in your MT Civic but half the effort.

locutus
03-05-2007, 07:13 PM
Hi brick and philmcneal,

145F is about 63C. (http://www.google.com/search?q=145F+in+C&ie=utf-8&oe=utf-8&aq=t&rls=org.mozilla:en-US:official&client=firefox-a) That's the part I don't get - it's not even a nice even number :)

Likewise on my <7 mile commute I don't usually get out of S3. I've got the forced-EV transition down pretty well so I trigger it about a second before I transition to glide (I've got the coastal 2-second cruise control cancel mod). Seems to work just as well. I hit 35MPH when I can in a few places, but mostly I like to hold it below 34 and just go in and out of EV.

The full stop to get to S4 is annoying. Only if I've got a known long stop and a big part of whatever trip I'm on left will I bother. ;) Otherwise it's all "fas-switch". :D



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