JohnO wrote:
On May 28, 10:50 am, " wrote:
Worth repeating. (Originally posted to the AirVW Group)

Alcohol in fuel

Alcohol has a lower BTU value than gasoline. Depending on how much
they are adding to your fuel, you are going to be seeing less power.

Alcohol is hygroscopic; it absorbs moisture and holds it in
suspension, further reducing the energy content of your fuel but also
exposing your fuel system to corrosion.

Alcohol weighs less than gasoline. The stoichiometric ratio of an
Otto Cycle engine is based on the MASS of fuel & air. If you have a
fuel-injected engine with an on-board combustion-control computer, the
system will adjust itself automatically and the only thing you'll
notice is that you must now buy/burn more fuel to travel the same
distance or do the same amount of work. If you are using a carburetor
you will have to re-size your jets to accommodate this lower-energy
fuel.

Depending on the type of alcohol being used to adulterate your fuel
(ie, methanol or ethanol), your fuel will now have a higher
endothermic ratio to achieve vaporization. With pure gasoline the
endotherm is about 90 degrees on the Fahrenheit scale; alcohol is
between 120 and 140. Given that alcohol is also hygroscopic, you will
have to re-size your carb & manifold heating arrangement to prevent
icing.

Alcohol has a higher octane rating than straight-run gasoline (about
120 vs 80). If alcohol is the only fuel you can afford (ie, as with
Brazil) then you can increase your engine's compression ratio to take
advantage of its higher octane. But this is not practical with an
engine originally designed to use unadulterated gasoline.

-----------------------------------------

Adding alcohol to gasoline is a TERRIBLE idea, especially for
aviation. Large corporations bribed our Congressmen to subsidize the
building & operation of the necessary distilleries to ensure a
built-in margin of profit. Since the average American is a virtual
idiot when it comes to technology, they simply told them alcohol was
'environmentally friendly' to sell this particular scam to the public.
In fact, mixing alcohol with gasoline is an environmental disaster
since we will now have to burn more fuel (and generate more pollution)
to do the same amount of work or travel. The subsidies amount to
about seventy cents per gallon of alcohol and are in fact a hidden tax
imposed on anyone forced to use this adulterated fuel.

-R.S.Hoover

And not only that, it makes your martini taste terrible.

Reminds me of the cotton gin. Who wants a fluffy martini?

Dan, U.S. Air Force, retired