[net.auto] Methanol/Gasoline Blends - GM Warning

res@ihuxn.UUCP (Rich Strebendt) (03/30/84)

A short while ago there were questions on the Net about the effects on
cars of the use of gasolines containing alcohol.  I was at my local
Pontiac dealer this morning and picked up an interesting "Customer
Service Newsletter" devoted to this question.  Since the publication
contains the notice " ... Material may be used at will." I reproduce
selected portions of it below.  If you would like a copy of the entire
publication, it should be available from your local GM dealer, or
from the Public Relations Staff, Rm 11-226, GM Building, Detroit MI.
(no ZIP code given in the document).

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... Vehicle performance and fuel system durability with gasolines
containing up to 10% ethanol [grain alcohol], by volume, have generally
been satisfactory.

... current use of methanol [wood alcohol] in gasoline can pose
problems if used in today's cars over an extended period - even at low
methanol concentrations in gasoline. 

... There is limited information that suggests small amounts (up to
around 5%) of methanol in gasoline may be suitable if a cosolvent - an
ingredient that prevents the gasoline and methanol from separating when
trace amounts of water are in the fuel - and a corrosion inhibiter to
prevent damage to the fuel system components are used.  Evidence on the
suitability of such blended fuels is incomplete and, therefore, their
use cannot be endorsed by GM at this time.  

It is likely some engines and fuel systems will be sensitive to
methanol/gasoline blends that contain higher concentrations (greater
than about 10%) of methanol - even if the fuels contain cosolvents and
corrosion inhibitors.

... The U.S. Environmental Protection Agency (EPA) has granted waivers,
legally allowing the blending of methanol ... [in] concentrations as
high as 12%, as long as cosolvents are used.

[EPA investigation has turned up instances of legal concentrations of
methanol without cosolvents, and also instances of as high as 15%
concentrations of methanol.  This is encouraged by the fact that
methanol is much cheaper than gasoline at this time.]

... There are a number of disadvantages associated with the use of
methanol/gasoline blends in vehicles designed for gasoline.  Of major
significance are:
	o  Deterioration of fuel system materials [rubber, plasic and 
	   metal parts]
	o  Driveability [tendency toward vapor lock]
	o  Separation  [alcohol/water layer formation]
	o  Fuel economy [poorer milage on methanol]
	o  Evaporative Emissions [due to increased vapor pressure]

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Note that there seems to be no problem with gasohol (gasoline +
ethanol), but that some companies are cutting their gas with methanol
which could cause problems.

					Rich Strebendt
					...!ihnp4!ihuxn!res