Acetone. Lets get to the bottom of this

[JohnnyGrey]

That's not my experience using one in controlled conditions. The last series of back-to-back runs I did testing vortex generators had a standard deviation of .6%. I'd call that decent resolution. It's less important that the absolute MPG readings are 100% accurate, as long as the relative differences are consistent.

Don't confuse resolution with accuracy. SG only correctly accounts for stoich, no other mixture. Even then, it's flawed. Just because it ends up being pretty close when you fill up doesn't mean that trip averages in certain conditions are accurate. While it can be accurate for external factors like aero drag, it cannot give results for things that affect the quality of combustion, like lean burn and acetone. Because it is an air meter, it can't tell you that you traveled the same distance using less fuel. If you used the same amount of air during that trip, it will report no difference.

[ihatejoefitz]

The fact that you already believe it works will be detrimental to your cause. You need somebody who doesn't really care, either way.

[johnpr]

i dont care either way... but why do you keep claimning that ethanol is damaging??

[trikkonceptz]

mechanically ethonal is not damaging, it simply reduces FE. Not the most FE solution to our dependence on oil.

[MetroMPG]

Originally Posted by JohnnyGrey

While it can be accurate for external factors like aero drag, it cannot give results for things that affect the quality of combustion, like lean burn and acetone.

That's true. I missed your point in relation to this thread.

[johnpr]

Originally Posted by trikkonceptz

mechanically ethonal is not damaging, it simply reduces FE. Not the most FE solution to our dependence on oil.

ok, thats what i thought, i have used ethanol for years with no bad side effects, and switching from 10%-20% eth in my jeep (jeep 2) did not harm mpg but ehh thats a whole discussion on its own so i will leave that alone...

[DifferentPointofView]

Using ethanol brings me down from almost 24 down to 19-21. And if you figure it out, that loss isn't worth the 10 cents a gallon less. Ethanol needs to be cheaper/BTU's before it replaces any part in gasoline (even mixing).

[Daox]

If engines were specifically designed to run on E10 gasoline (higher compression) you wouldn't see much of a loss in mileage. This is probably the way things will go eventually. However, right now manufacturers need to make an engine that can run on both forms of fuel and that is a compromise that costs us mileage.

[johnpr]

DPoV what mixture of ethanol are you using?? i had a chrysler T&C (flex fuel) and i ran e85 on it and didnt see that much of a loss (maybe 2mpg), as is any modern vehicle should not see much of a difference on e10.. but if your vehicle is not calibrated for e85 and you try to use it you will have a huge difference because your computer will read the exhaust as being lean and will dump more fuel in to compensate for the perceived lean state.

[tasdrouille]

Originally Posted by JohnnyGrey

Don't confuse resolution with accuracy. SG only correctly accounts for stoich, no other mixture. Even then, it's flawed. Just because it ends up being pretty close when you fill up doesn't mean that trip averages in certain conditions are accurate. While it can be accurate for external factors like aero drag, it cannot give results for things that affect the quality of combustion, like lean burn and acetone. Because it is an air meter, it can't tell you that you traveled the same distance using less fuel. If you used the same amount of air during that trip, it will report no difference.

What if you divide the MAF value by lambda (assuming you have an accurate lambda value)?