+1.

+1.


At Colorado altitudes you need at least 2 less octane points to prevent damaging knock because of the atmospheric pressure (your power is also down). Fuel system materials are now designed with ethanol in mind (NOT METHANOL), but given it's lower specific heat content, you don't get the same fuel economy as with a straight petroleum based fuel. The days of tetra ethyl lead fuel additives are gone. Today's octane enhancers will not exponentially increase octane but do so pretty much on a linear basis. That means you'd have to add 4 gal of 100 NL racing fuel to every 10 gal tank of fuel to get from 85 to 91 octane. Even a super high octane additive will have no more than about 120 octane and would take a full gallon to raise the octane 3 points when added to 9 gallons of 90 octane fuel.

 

Thanks everyone! Good info!

 

Yep, I'm with Stohlen and Unhinged. ....it can't be stressed enough that the canned octane boosters are a complete waste of time and money.

While ethanol is fine is regular use in our cars, it does degrade more quickly than non ethanol fuel and since my car sits for up to 6 months at a time and I'm lucky enough to have several sources available, I use either Chevron 94 non ethanol or Shell 91 V Power non ethanol. YMMV

Dave

 

This is only a factor with 'vented' fuel systems (boats, garden tools, some motorcycles or pre-1970 cars). Modern cars have sealed systems eliminating direct exposure of the fuel to air. Degradation of ethanol fuels under such conditions is similar to non-ethanol.

 

This is 100% false statement.

 

We've been over this; short answer is that I don't believe you. Even "sealed" systems still have air in them ....and even if I was wrong, you can't give me even ONE advantage to running ethanol contaminated fuel.....ergo, I'll continue with my non-ethanol choices.

Dave

 

You're right- there is no advantage, but not everybody has access to ethanol free fuel. My comments were to avoid setting off a panic about storing modern cars with E10, as per common internet myth.

The amount of air in the tank has a finite amount of moisture in it, I'm sure you'll agree. That moisture will be absorbed over a period of time and suspended in a harmless manner by the ethanol in the fuel.

Not sure if that's not a better situation than the same amount of moisture remaining suspended in the air space above the fuel when using pure gas.

If the gas tank was vented directly to the atmosphere, then you'd be right to avoid E10 during storage. I drain the tanks of my gas powered vehicles/tools etc. that are so equipped.