Quote:
Originally Posted by ShadeTreeMech
Wow let's change the subject to why is taking ethanol out of gas helpful?
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I am not a chemist or fuel engineer I really don't know "factually".
Here is my best educated GUESS as to why it helps.
My engine is NOT designed to operate on ethanol. SO it runs very poorly on ethanol. So much so that the presence of ethanol "interferes" with the ability of the engine to extract mechanical energy from the combustion of the fuel but not enough to prevent it from running at all.
It would be like mixing a few gallons of diesel with your cars gasoline fuel. it would still run but it would run like crap.
The BTU energy of the fuel is only relevant in a PROPER operating environment.
Our engines (at least those of us having issues) are NOT in a proper operating environment with the presence of E10
The current hypothesis (NO testing this is PURELY guess work here) is that when the spark plug fires it is NOT igniting the ethanol reliably. The gasoline lights and the flame front from the gasoline then "burns" the ethanol. alas this happens "late" so you get two competing flame fronts inside the cylinder.
the REASON we "guess" this is the case from one single example we found. I have NO idea where I read this I thought it was HERE but I could not find it again. it might be on the other ethanol thread I am on but its not searchable and is many many pages long.
Someone with either a 2004 or 2006 (can't recall which) Hybrid SUV was experiencing a nearly 30% drop in FE using E10 even though his vehicle is rated for Ethanol usage.
He took it to the dealer and they "fixed" the problem. when he asked what they fixed he claims this was the response.
The Computer was programmed incorrectly and the spark was too weak to properly light the ethanol mix. The programming was corrected to use a hotter spark as is proper and now it functions properly.
He reported back that now he only see's the "expected" 4-5% drop in FE when using E10.
This is how we came up with the spark being "part" of the problem with Ethanol mixes in older engines.
No real science here just an observation and an educated guess.
SO the current assumption on our part (those of us having problems) is our cars can not properly COMBUST the ethanol mix so when we REMOVE the ethanol of course PROPER combustion resumes. IE we are NOT extracting the expected number of BTU's from the fuel as the math assumes.
IE our thought is this is NOT about the lower energy content of ethanol we all agree its only a 4% or 5% difference for our cars.
its the IMPROPER COMBUSTION of this mix that is leading to the losses we are seeing. NOT the lower BTU content.
I thought about a newer custom higher powered ignition system but WOW anything decent costs more than I paid for the car so thats not an option anytime soon so I can not TEST this "hotter spark" assumption.