Does anyone know if this stuff has an adverse affect on our engines? There are a few stations around here that have 94 octane gas but it has a 10% ethanol rating. My cousin (who drives a crotch-rocket) says never put gas with ethanol in any engine. My friend says it is fine and I shouldn't worry about it. Does anyone know where our Suby's stand with this stuff? I have been wondering this for a while now....

 

Your cousin is retarded.

 

No, your cousin is not a retard and actually he is right.

Use it on your own risk.
Damage from improper fuel is not covered by the warraty and Subaru states that methanol or ethanole mix could cause engine mulfunction, fuel system problem, fire caused from corroded fuel system from the improper fuel (depending on the ethanol/gas ratio too).

What fuel is included in `proper` ones varies from manufactures and each has its own policy. If something happens you gotta pay for it, or go through the pain to prove that the gas you used is accepted.

It will probably work but I'd avoid ethanol mix to avoid the hassle just in case.

 

From what I understand, using a too-high octane fuel (such as race gas or gas with tolulene or an octane booster added) can seriously degrade your catalytic converters and cause them to break down. Since the WRX has a cat BEFORE the turbo, an unusual location for a catalytic convertor, a breakdown of this cat would be especially nasty (and cost you a $700 turbocharger).

However, ethanal is a totally normal gas additive, used to "oxygenate" the fuel and promote clean combusion. Even the 87, 89 and 91 here in Arizona uses it as an additive.

 

Beside that, the ethanol is sorta a solvent so it tends to eat away at most plastic or rubber parts. I've also heard that its bad on the valves? Not sure on that one though.

 

Your friend is correct - even Subaru agrees with him! As long as the ethanol is 10% or less, it's not a problem - just read your owners manual:

"Many gasolines are now blended with materials called oxygenates. Use of these fuels can also help keep the air cleaner. Oxygenated blend fuels, such as MTBE (Methyl Tertiary Butyl ether) or ethanol (ethyl or grain alcohol) may be used in your vehicle, but should contain no more than 15% MTBE or 10% ethanol for the proper operation of your SUBARU."

methanol is another story - Subaru says:
"Methanol (methyl or wood alcohol) is sometimes mixed with unleaded gasoline. Methanol can be used in your vehicle ONLY if it does not exceed 5% of the fuel mixture AND if it is accompanied by sufficient quantities of the proper cosolvents and corrosion inhibitors required to prevent damage to the fuel system. Do not use fuel containing methanol EXCEPT under these conditions"

In the winter out here, I don't think you can even buy gas which doesn't contain ethanol...