How much does a Prius' pip weigh?

[diamondlarry]

Originally Posted by Dan

Basically you get a flashing PIP until you run out of gas. Then you get a red triangle and the ICE shuts off. If you have enough SOC you got about a mile to find a service station.

I'm basing the 2.5 gal at flashing on Larry's KiloTank. He flashed at 820 but still made it to 1000. My math puts it at over 2 gallons. But the CAN traffic says you have about 1.5 gallons at flashing pip. If you want to watch wat the CAN traffic thinks your fill level is, plug in the new XGauges and you get a "gas" gauge that tells you the % full your tank is (0-100%).

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PS. Pip flashes at between 12.5% and 15%

Dan, the pip started flashing at 892 miles and I went to 1052.8(FCD) and took 12.4 gallons. I'm guessing that will make a significant difference in the calculations. You are doing some awesome work here and I can't wait to see it when it's finished.

[Aether glider]

Larry,
Did you run it out of gas that time? I imagine you were very close if you filled with 12.4 gallons.

I"m starting to have my doubts about this tank for me.

[diamondlarry]

Originally Posted by Aether glider

Larry,
Did you run it out of gas that time? I imagine you were very close if you filled with 12.4 gallons.

I"m starting to have my doubts about this tank for me.

No, I made it in on my own power. I heard over the weekend that as much as 13.0 gallons have been reported to have been pumped into a Prius. I think it was at fuel-starve though.

[Aether glider]

I should reach fuel starve in 5-6 days

[Dan]

My observations of CAN id 0x244 in relation to the gas gauge....

The pips fall whenever the "gas" XGauge (0x244) crosses a certain threshold. That threshold has to be held for some period of time before it's committed to the PIP display. For example, I was driving along at 15% (0x06 on 0x244 byte 8). I dipped down to 12.5% (0x05 on 0x244 byte 8) for a few seconds then it bounced back to 15%. The next day it stayed at 12.5% for about 30 seconds and I got the "Add Fuel" message. I suspect it latches at 30 seconds or a minute. Now resurrecting a pip has happened, but never to me. I suspect the "latch" timing is much longer. Something like 30 seconds to latch on the way down, but 5 minutes to latch on the way up.

So basically, if the CAN id 0x244 drops to 0x05 (12.5%) for 30 seconds, you go from solid pip to flashing pip. I theorize that if your car got sufficiently tilted for say 5 minutes and CAN id 0x244 continually registered 0x06 or 0x07 then you would get that last pip back eventually.

Now the XGauge "gas" gauge does bounce around a lot. As much as 5% on any trip depending on terrain, but watching it gives you complete transparency as to how the PIP display is being derived.

PS... Larry do you recall what the FCD MPG was at flashing pip and what it was at fillup? Basically what I need are two pip points where each pip point has FCD MPG and FCD miles. From those four figures I can weigh a pip.

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[diamondlarry]

Originally Posted by Dan

PS... Larry do you recall what the FCD MPG was at flashing pip and what it was at fillup? Basically what I need are two pip points where each pip point has FCD MPG and FCD miles. From those four figures I can weigh a pip.

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Unfortunately, I don't have exact numbers for the FCD MPG for those points. When the last pip started flashing the FCD would have been in excess of 87 mpg. At fillup, it was 88.? but I'm thinking it may have been 88.3 but not sure. I'll keep a closer watch on this tank.

[Aether glider]

Dan,
Would you prefer the pip data as they fall or just when we finish a tank send it all to you?
I would assume a tank at a time.
PM or post it here?

How much data you going to gather before you start posting results?

[Dan]

Here's the averages between myself and AG.

PIP	Gallons	Liters	Standard Deviation %
1st pip	3.090	11.70	21.96%
2nd pip	0.553	2.09	11.63%
3rd pip	0.511	1.93	8.29%
4th pip	0.590	2.23	9.97%
5th pip	0.724	2.74	3.52%

Soon I will post this as an excel file in the "files" section. I got no problem with people simply posting the values to this thread. If you want, just put your tank in one post and edit the post as the pips fall. That's what I'll do. It is interesting that pip 5 is definately showing up as heavy. We both showed it as a heavy pip and the std. dev. is relatively small.

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[Aether glider]

Interesting how the standard dev is dropping as the tank gets further along. I guess from different fill levels?

I have a long drive tomorrow should lose 2 more pips.

btw...Hooked my Sgii back up in the prius gas xgauge is working...its showing a value of 55.0. I guess thats out of 100?

[Dan]

I expect the variance on the first pip to be huge since it's a matter of how well you stuff the tank. As suggested earlier, I think that most Prius will have the same amount of gas in the tank once 9 pips are showing. It will be interesting as more data falls in place.

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