Okay - I read the octane post and I get it - never anything less than 91. My question is about ethanol. I have noticed some of my favorite high end gas stations moving to higher ethanol levels - usually 10%. Is ethanol a bad thing? What limits should I look for?

 

In the old days ethanol softened and sometimes actually dissolved the butyl rubber pressure linings in automotive fuel systems. In the 1990s manufacturers changed the formulations of those linings to permit the use of ethanol as a gasoline additive. Thanks to federal tax subsidies, most gasoline sold as fuel in the U.S. now contains 10% added ethanol. This reduces the amount of foreign oil imported and increases the octane rating at the pump. It also reduces overall fleet fuel economy by a small fraction because ethanol contains less energy than pure gasoline.

All C6s are designed to use gasoline containing no more than 10% added ethanol. They might tolerate up to 15%, but the manual says 10%.

 

10% ethanol is fine.

We've had it at essentially every gas station in Houston for probably 8 years now.

 

Ethanol everywhere in Chicagoland area

 

Yep. Been here in the corrupt state of Illinois forever too.

 

We still get pure gasoline in Pennsylvania, at least that is what it's advertised. Who is to know. The cost is $.30 higher than regular pump fuel with E10.

 

We have a few ststions here in Central Alabama that advertises 0% ethanol. Costs a little more but worth it if you dont have to go to far out of the way. It provides better fuel milage and more power and is generally better for your fuel system. Wont make much difference. I use it in my Harley and will continue as long as it is available. I put it in the Vette if I get the chance.

 

I only purchase ethanol free premium here in Missouri. I run 94 octane in my Z06 and 91 octane in my 56, 64 vettes and in my Mercedes(premium required because it is supercharged).
The only thing in my garage that gets 10% ethanol crap is my riding mower, but I drain the gas tank and run the carb dry before I store it for the winter.

I'm one of those who can average 30 MPG cruising on the highway at 70-75 MPH in my Z06. If I ran ethanol in the Z06 I would see more like 28 MPG average on the highway at 70-75 MPH.

 

How can you tell you are getting ethanol free fuel. It is my understanding that in MO they do not have to state on the pump that the fuel contains ethanol.
Also, where are you lucky enough to find ethanol free?

Thanks,
Withering in Liberty

 

You have to ask the store manager. Here in Springfield, Rapid Roberts Conoco(91 & 93 octane), Eagle One Phillips 66(94 octane), and Signal(91 octane) plus a few no brand stations sell ethanol free premium. Missouri law allows stations to sell ethanol free premium. It's up to the individual stations to decide if they want to.

Also check http://pure-gas.org/index.jsp?stateprov=MO for other towns in Missouri.

 

Ethanol cantains more energy and burns cooler than gas. But it takes more of it. One of the things you have to do to convert to e85 is go to bigger injectors.

 

You might want to revisit your physics.

One gallon of gas = 116,090 BTUs
One gallon of ethanol =76,000 BTU's.

It takes 1.53 gallons of ethanol to equal the energy of one gallon of gasoline. That's why it's necessary for the bigger injectors. You have to inject more ethanol to get the same amount of energy that gasoline contains.

 

The **&^%%%$$(((***!!! politicians and tree huggers got the government to make it 15%.Happening now or soon anyway!
Here's something interesting I got in an email.Click on your state.

 

The tech at my dealership said that 10% ethanol is OK as long as the car doesn't sit for long periods of time. This gas doesn't age well.

Tom

 

Speaking of Liberty..... The name of the convienence store chain here in the Central Alabama(Montgomery) is called LIBERTY. Here it is required to be labled on the pump.

 

Ethanol has been mandatory in CT and NE states for over 10 years. Never a problem in any cars - including a HP '62 Corvette, 2000 Corvette and 2009 Corvette.

 

Total Bull - my '62 sits for over 6 months at a time and zero problems using ethanol gas for over 10 years. Your tech needs better education on the subject

 

I don't know the facts on aging fuel, either pure gasoline or ethanol but I do know that condensation build up can present a problem. Whether the resulting water residue is only condensation or a break down of ethenol matters little to me. I only know as a snowbird that my 6 month sitting cars always get some dry gas before starting just in case.

 

Okay, I'll weigh on this one. His tech is actually quite right.

I've worked for 2 different "Big Oil" companies over the past 10 years. Ethanol is currently used as the "oxygenator" in the areas of the country that require that. This is generally the bigger metro areas that have air pollution issues. You won't find pure gasoline in those areas. E10 is also used in outside of the bigger metro areas, but you might find some pure gas if you want it. However, if you area doesn't have it now, you likely will soon because the refiners are required (by EISA of 2007) to ramp up their use of Ethanol over the next few years. E10 limits the amount of Ethanol that they can blend to about 12 billion gallons/yr. (known as the "Blend Wall"). EISA requires them to blend more than that starting this year (2011 require 13.95 billion gallons and 15.2 billions gallons next year). The only way to raise the blend wall is to increase to E>10 or push Ethanol in to areas that it currently isn't. There are a lot of issues involved in going to E>10, not only with cars, but fuel storage equipment, pumps, lines, etc. Something has to give. If I haven't bored you enough, you can take a look at these links.

A good wikipedia write up on EISA:

http://en.wikipedia.org/wiki/Energy_...ty_Act_of_2007

And a good description of the blend wall issue:

http://www.pmaa.org/userfiles/file/L.../BLENDWALL.pdf


Now, this is why I think his tech is right. We used to worry about condensation in the gas tanks of our cars because we didn't want the tanks to rust out over the years. That isn't really a problem in today's cars, but condensation now causes another issue. One of the biggest problems with Ethanol is that it loves to bind with water. When it does, the water becomes suspended and forms a cloudy mess that really doesn't burn at all. I believe his tech is pointing that out.

Moral to the story is that you are probably okay storing your cars with E10 in the tank for a few months, but it is important that your tank be full if your car is going to be subjected to temperature variations that will cause condensation in your tank.