LATE THOUGHT:
I'm saving copies of the source data, CSV format, in the YahooGroup, "Prius_Technical_Stuff" in an open, shared, data folder. I'm not sure how Ecomodder prefers to handle data sharing and I'm not a great fan of using 'attached files' as they tend to get 'lost'. I'm not pimping the other site as much as sharing where folks can find the source data for these charts. <wink>
ORIGINAL THOUGHT:
We had a side conversation and we agreed to share this:
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Originally Posted by suspectnumber961
Actually the way you explain things forces anyone interested to actually try and understand the graphs and your comments...I kept wishing you'd end by writing a simple synopsis and conclusion...but that would be too easy! Seriously.
Still not sure how you'll account for variations in gas quality for the MS test...just that you've determined that there are variations. This leaves a lot of room for......guess what....fuel additives. ;-)
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What I'll eventually have is:
- fuel burn rate - baseline oil before treatment
- % - 2nd tank vs 1st tank
- % - 3d tank vs 2nd tank
- fuel burn rate - baseline oil change after 1,000 miles
- raw % - post 1000 miles vs baseline oil (raw!)
- net % - sum of three percentages (adjusted for gasoline effects)
When I have the numbers, I'll have to be very careful about the signs but the math is fairly simple. But here is a simple example.
2.6 gm/sec - baseline oil burn rate
2.6 gm/sec - after 1000 mile change burn rate
0% = (2.6-2.6) / 2.6 :: no change in fuel burn rate
2.7 gm/sec - 1st tank burn rate
2.8 gm/sec - 2nd tank burn rate (fuel has less energy so more is burned)
-3.57% = (2.8 - 2.7) / 2.8 :: 2nd tank has -3.57% energy
So if the ending fuel burn at the end of the oil test is the same but the gas has -3.57% less energy, then there was a reduction in drag of -3.57% due to the oil additive. . . .
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Originally Posted by suspectnumber961
LaPointe just hated those lightweight oils...but I never saw any gains from using the heavier stuff like he mentioned. So I guess it's lighter oils and oil additives for me.
But this is the first car I owned where it might have the sensitivity to show some results...but since it is a ULEV...the O2 after the cat might be controlling the fuel mix more than with the regular version? Tail pipe is white glove clean...but the tops of the pistons...even after Techron were carboned up....so a lot of fuel is burned in the cat. The 2011 version (with more HP) gets 34 highway vs 28 highway for the 2003....so higher fuel prices and some legislation automagically forced them to find a few more mpg....looks like they found some of the "if it worked the car companies would already be doing it" mpg?
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I admit sharing this thought. If something is so dang good, it would make sense to have the manufacturer put it in.
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Originally Posted by suspectnumber961
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Originally Posted by bwilson4web
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Originally Posted by suspectnumber961
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It's my opinion that fuel use could be reduced substantially by overall use of fuel and lube additives in the US...probably cheaper than invading countries.
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I read a 2010 EPA report that makes a similar claim about fuel savings although they were advocating use of 0W-20 grade oils.
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Originally Posted by suspectnumber961
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I really appreciate the testing you are doing and the graphs...though they are a bit hard to interpret at times...
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Some of it may be 'cognitive style,' still, feel free to point out where I could improve them. <grins>
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Originally Posted by suspectnumber961
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So you think that measuring MAF under similar conditions indicates a reduction in friction and/or a gain in "power"? You are assuming that less MAF = less fuel being used at stoich? Which by definition is the case? Which is why you want to start from the thermo opening? Wondering if the air/fuel ratio is being held stable? Should be.
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A couple of years ago I plotted injector timing x rpm versus MAF and found a linear relationship. Furthermore, the catalytic converter depends upon a slight oscillation about the stoichiometric ratio to convert HC, CO, and NO(x) emissions to CO(2) and H(2)O. It is a dynamic feedback loop so I know it is effective.
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Originally Posted by suspectnumber961
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I'm thinking that using the thermostat opening and taking an average for MAF out X minutes from that point might be most accurate? But then this might be similar to an mpg readout?
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For a quantitative number, that would work. I just find it easier to use a horizontal line and 'eye ball' it. I doubt there is much error.
Bob Wilson |
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