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Originally Posted by gteclass
I have not looked into the surface tension specs. Where did you get those? Are they for pure gasoline or are they from a specific oil companies MSDS on the gasoline they sell in the pump with all the additives?
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This is where I got my information on the surface tension of gasoline.
http://www.newton.dep.anl.gov/askasc.../mats05037.htm
This source says gasoline has a surface tension of 20
http://www.corkind.com/ttn/cttn_12_9...ace_Energy.pdf
An exact number cannot be pinned down because there are different formulas, mixtures, etc for gas and even then the mixtures may be adjusted seasonally.
On page 1 is a breakdown of gasoline's components by weight
http://www.jdm-inc.com/files/Gasolin...ventional).pdf
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The surface tension claim comes from the sources that i listed in my original post. Also, I have seen many chemistry experiments yeild physical property changes that were not in any way averages of the properties of the components of the formula.
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According to part 4 of this analysis that claim won't hold when mixing acetone and gasoline.
http://neubranderinc.com/blog/2007/0...oline-concept/
In this case the author could not find an exact value for gasoline and chose to use an average of the surface tension of gasoline's components.
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Also, where did you get this most cars burn 98% of their fuel idea from. Is this including the large percentage that gets burned off in the catalytic converter?
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This information I got from a mechanic a couple years ago. However I did find an article on motor scooters which don't have to meet the strict emissions levels cars do and don't have catalytic converters. A 1968 2 stroke scooter emits 0.49% unburned hydrocarbons. A more modern 2 stroke scooter emits 0.11% unburned hydrocarbons. A modern 4 stroke emits 0.0168% unburned hydrocarbons. To get the percentage of unburned fuel I think we need to multiply these values by the stoichiometric fuel ratio of 14.7 for gasoline engines. So that results in 7.2% , 1.6%, and 0.25% of the fuel left unburned respectively. Granted these are motor scooters and not car engines however the budget for developing car engines is much greater than the budget for developing motor scooters. Also the technology employed to burn fuel efficiently and completely is far more advanced in a car engine than it is in a motor scooter. From this data I think it is safe to say cars burn 98% of their fuel.
http://wweek.com/editorial/3240/7867
Note: I think the author has CO2 confused with CO emissions
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If it does cause the fuel to burn quicker then the ecu will see any knock and retard the timing which doesnt really mean anything by itself about fuel economy. Timing is all about making the flame front hit the piston approximately 15degrees after TDC. If the flame front moves faster, this would be a good thing as long as it still reaches the piston at that point.
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An engine that has its timing retarded produces less power per unit of fuel and thus runs less efficiently.
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The car may immediately start adjusting, but it takes about 200 miles for fuel trims to stabilize and even when they do, any little change will cause it to adapt more. Thats at least a half a tank no matter what you drive before the ecu actually knows what its doing.
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We will have to agree that we disagree on this. Cars adjust rather quickly to changes in altitude and weather. They have to to meet emissions.
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trikkonceptz's procedure definitely could have been improved by using 4 consecutive fill ups with each step and averaging the results ignoring the tank of gas that the ecu is in transition mode. I am conducting my own experiment right now using this method. Ill post the results as they come it.
Also, try comparing a 80s economy car... say a 1986 honda civic with say... a 2006 Honda Civic. Or how about a 1986 Toyota Corolla with a 2006 Toyota. Of course with a high end luxury car your not going to see great gas mileage in the 80s.
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I thought I might spend a moment debunking the source of this myth. If you look at the different versions by the originator of this myth you will see that he claims to have 50 years of data on this.
http://web.archive.org/web/*/http://...s/additive.htm
However despite having 50 years of data his acetone ratios change wildly in the first 6 months and he claims that the ratios must be precise. He claims that he isn't in this for profit and he is giving these findings to the world for free. This was a half truth, at the time he was selling scan gauges for people to try and verify this myth. He is essentially pulling off the classic scam of giving away a fake treasure map and selling you a shovel.