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Has anyone found or tried to find a value to drive to which would indicate no pack draw while accelerating available on a scan gauge?

Like IGN or TPS or RPM ?

I've been trying to figure it out but nothing seems to be consistent (due to SoC management?).

If you are drawing off the pack at say ign 15/rpm 1600, would you lift off or ask for more power to get off the pack?

Any science involved? I'm thinking it might be what I need to master to get over 70mpg.

Sup'd, I can't claim to be an expert here but I can tell you what I did for a week with Jud's vehicle, and I was often over 70mpg in that car. I found I could not accelerate from a stop without pulling some assist. Once I hit about 13-15mph though I was able to "feather" the pedal to get the mimic to stop displaying any assist. Anytime I saw it above that I would back off the pedal until it stopped, then ease back into it. Some hills were too steep to get this to work of course, but in general that worked quite well.

I kept my SOC at 4 or higher bars -- that may help with the SOC management? I didn't dip below so I can't tell you for sure if there is any difference.

The approach is basically what I do in the Honda hybrids -- if assist appears, back off. Unlike the Hondas though, I don't think you can convince the Prius to stop giving you assist at higher loads.

My best trip in the car was 94.6mpg over 18mi... and I had 4 of 6 bars pegged with the other 2 just barely below the top at one point. Without the warm-up hit it would have been over 100mpg.

I hope that helps?

Sean,

That's basically it in a nutshell. You have it down.

Sean's got it. Few things to add.

Acceleration WITHOUT assist is impossible at 8 bars SOC. Acceleration WITH assist is impossible at 1 bar SOC. So in essence with or without assist is basically a SOC question. I'm always at 4 bars (49-54 % SOC).

So first thing to do is get to 4 bars. If you have an EV button, EV from 0-15kph (9mph), then disengage EV to light the ICE. For the first 500 ms the ICE light will kick bumping you up to 16-17 kph (10 mph). From here you can "catch" the kick and do a slow acceleration. You can test this with 4 bars by seeing how slow you can accelerate. Try to accelerate about half as fast as a dump truck to start with.

I honestly find acceleration experiments impossible in MPH. The units are just too big. The ECU also tracks in KPH and converts to MPH. Going from 0-12 mph the speedo only "ticks" 12 times. But in KPH, it "ticks" 20 times. Also there are certain "hickups" in the MPH display. For example 31 if you are at a constant acceleration rate of 0.62 mph / sec you will see 30 mph on your display for 2 seconds, 31 on your display for 1 second, and 32 on your display for 2 seconds. It will look like there was a "hickup" at 31.

Since I never speed, I rarely have to worry about breaking the speed limit. There is no minimum speed in Harris County either ;).

11011011

in my 04 prius i can do this without any thought, just feel the load of the engine, if its working hard (not at high rpm but at high load of the current rpm) and the speed is increasing with moderate time, then its probably putting all the power towards the wheels.

In the prius the pedal is programmed to three things i noticed

a) ev mode (Stage 4 is achieved in warm up cycle)
b) cruising with engine power going into the pack
c) acceleration to the wheels only (if S.O.C is less than 60% then more to the pack, if higher than more to the wheels)

at anytime you are accelerating from a dead stop these values will change as speed increases, so to compensate just gradually increase pedal pressure ( don't worry your FE won't be killed by that much because 1) your in efficient rpm and 2) even though your using more fuel, your speed is increased to compensate)

once you reached optimal speed you can go back to ev mode so a hypermiler would use A and C most of the time, using B if one knows their S.O.C is low and there are no regen opportunities to take advantage of.

so to recap, if you want accel to wheels only accel with good rpm (1500-2300 is sweet spot) and then as soon as you get the arrows to wheels only maintain it and gradually increase your foot pressure as speed increases, if you don't increase pedal pressure enough you will go into cruising mode and if you accel too hard then you will suck juice from the battery to help you accel, so find the sweet spot then maintain it as speed varies!

hope that helps, once familiar enough people will just know at what pedal pressure at X speed will result in one of the three scenarios described above.


edit: i do notice at low speeds (starting from a stop) the power to the wheels is only achieved at very low rpms (1100-1500) and personally unless i KNOW i won't be stopping in the next few yards i'll just mass the throttle and let the engine at its sweet region, and once speeds are 20 mph or so then i'll proceed with the "Power to the wheels" on the MFD up to the speed I want to coast at.

Thanks for the tips, I've got it down now.

It seems that if you are asking for too much power at your current rpm but not enough that the computer wants to increase rpm, it will give pack assist. So either go up a click to the next rpm and hope you hit the right spot or back off slightly to request the amount of power that the ice is providing.