E15 fuel

[Arizona_928]

I just filled up with diesel, included a percentage of biodiesel at the pump...
Did not like...

[flipper35]

Originally Posted by pksystems

Sounds good. I wish we could get more ethanol in our gas. 94 octane (E10) locally was 157.9/L last time I filled up the turbo car. The engine going in my P-car loves ethanol.

Our 93 octane is E0 here. Good for the motorcycle, Cobra replica and lawn equipment.

[Por_sha911]

Anything that doesn't get used regularly is going to be hurt by ethanol in fuel. Lawnmowers, leaf blowers, the old pickup that only gets driven once a month...
Scientifically, E10 has less energy density per gallon so it takes more fuel to get the same power. How much it affects your car's mileage is not something you will see in a tank or two but use it for a year and you've spent money and gotten less.

[manbridge 74]

Originally Posted by Jesse16

I've recorded gas stats since the day I bought the car 10 years and 100 k miles ago so I know my mileage. A few times over the years I found pure gas and bought a few consecutive tank fulls and I've never found a difference in mileage or butt dyno feel. Can generally only find E10 in NC, pure gas is a Snipe hunt mostly. Shouldn't argue that it should be noticeable as I am an engineer, simply that at least in my car other variables must make it invisible.
Edit: Yes, that comment below is definitely true. The pump says max or ( up to ) 10% so no idea how much is in any tank I guess ? Kind of a weird call out for a fuel seems like but we're all used to it now.

Probably because its more like E5 at certain times for whatever reason. At least when I tested it here in CO.

[rockfan4]

La Crosse is the home base for Kwik Trip, a local gas / convenience store chain. The bad thing about that is that they've run all but about a half dozen competing gas stations out of business, so they set the prices in town. They sell their own brand of "Top Tier" gas. Earlier this year they started selling E15 gas, 88 octane, and dropped the 89 octane E10 midgrade. So now they sell the E15 at the same price the other stations sell their 87 octane E10, their 87 E10 is a nickle more, and they have a 91 octane E0 Recreation full that is right now about 75 cents more a gallon than their 87 E10. Get a few miles out of town and premium is only 20 or 30 cents more a gallon, I don't know if it has ethanol or not but I presume it does. In towns where they have competition they match prices with the other stations.

[masraum]

Originally Posted by berettafan

at one point I had thought e15 was actually 85% ethanol. guess I was wrong in that?

Correct, that would be e85.

[Por_sha911]

JUst to clarify, the problem with ethanol in items not used frequently is the absorption of water. All this is old news and accepted science. Why do folks still debate this?

[KFC911]

I'll burn E10 in my DD F150, but other things only get pure stuff....87, 90, 93 depending on requirements. Ethanol in gas just flat sucks, always has...always will. Yes, it reduces mpg...no debate either . I sometimes put pure gas in the F150 (87), if I happen to be at a station...the price difference at the pump here is negated .

[sammyg2]

Originally Posted by Por_sha911

JUst to clarify, the problem with ethanol in items not used frequently is the absorption of water. All this is old news and accepted science. Why do folks still debate this?

There are several problems with burning ethanol.

It has significantly less BTUs per volume, meaning you get less horsepower from a gallon of ethanol than a gallon of gas.

Stoichiometric for gasoline is just under 15 to one air to fuel ratio.
For E85* it's 9.9.
That means it takes a lot more gallons of E85 than it would for gasoline.
It could be argued that E85 has more potential because of anti-knock properties, but that only would come into effect with variable compression ratio, wide open throttle, etc.
IOW it would matter on a race car designed to take advantage of those specific properties.

The hygroscopic properties of ethanol were mentioned above, which makes ethanol tend to increase corrosion in engines. Not good.

Common elastomers that are just fine with gasoline do not do well with ethanol.
mostly an issue with older engines.

Some folks like to say that ethanol is less expensive than gasoline. Bull flop.
Ethanol is cheap only because the gubmint is subsidizing it, making it look cheaper than it is. we all pay.

Ethanol is made from corn. Corn is food.
Corn is food for people and food for things that people eat. Like cows.

Turning corn into fuel makes people food more expensive.
And that is dumb.

DISCLAIMER: I worked for Valero a long time ago and still own some Valero stock. Valero is an ethanol manufacturer/supplier.
I currently work in biomass-fuel R&D.


* E85 is higher concentration than E15, obviously. I used E85 as an example to demonstrate the difference between ethanol and gasoline.

[wdfifteen]

Originally Posted by AZ_porschekid

I just filled up with diesel, included a percentage of biodiesel at the pump...
Did not like...

I hear it's a little sweet up front, but bitter on the back of the palate.

[RSBob]

Sammyg2 great analysis and summary. the only thing you omitted was that ethanol does not burn as cleanly as gas and puts more crap in the air we and our children breathe. Asthma rates in children are skyrocketing.

[Por_sha911]

Originally Posted by sammyg2

There are several problems with burning ethanol....

Agreed to all the above. My posts were right in line with yours (albeit not quite as scientific - I try to put things in laymans terms). My point is this is all know and accepted science yet
a) Politicians still shove it down our throat (Trump screwed up this one)
b) People still ask what is the problem. Its been discussed here and elsewhere for years and nothing has changed in the scientific community to dispute it. Why is it still brought up?

[sammyg2]

My concern with the environmental issues of ethanol are not necessarily related to what comes out of the car's tailpipe.

I am more concerned with the emissions resulting from the growing of the corn, the harvesting of the corn, the processing of the corn, the distillation of the ethanol, and the transportation of all that stuff.
That process is net negative energy.
It takes more energy to produce ethanol than you get from the ethanol produced.

How could that possibly be considered environmentally friendly?

[DanielDudley]

Originally Posted by sammyg2

My concern with the environmental issues of ethanol are not necessarily related to what comes out of the car's tailpipe.

I am more concerned with the emissions resulting from the growing of the corn, the harvesting of the corn, the processing of the corn, the distillation of the ethanol, and the transportation of all that stuff.
That process is net negative energy.
It takes more energy to produce ethanol than you get from the ethanol produced.

How could that possibly be considered environmentally friendly?

I think they feed the tailings to pigs, which makes it slightly better I suppose. I don't really know anyone who is a big fan of ethanol in fuel, but I have been willing to tolerate it at 10%.

Once you get up past that, I don't really want it in my cars. If someone finds a petition, let me know, I'll sign it...

[berettafan]

using a food source to lower gas mileage in vehicles is just stupid.

[red-beard]

Look at this chart.

Rubber Chemical Resistance, Rubber Chemical Compatibility, Page 3 - Mykin Inc

Butyl and EPDM are fine. But Viton is attacked

[brainz01]

I've changed my views on ethanol a bit over time (from staunchly opposed to more accepting). I agree with everything Sammyg2 said -- them's the facts. And has also been said, the stuff is particularly bad for older, infrequently run, carbureted engines. But as a car guy, I'm not convinced it's all bad, particularly as cars are increasingly going to smaller turbo charged engines to meet emissions and fuel economy requirements.

Modern turbo engines love [need?] octane and ethanol is a safe/cheap octane booster (at the potential expense of a modest reduction in fuel mileage). My vehicle fleet is currently all twin turbo engined. Every one of my cars perks up with higher ethanol content, even the GL450 and CayenneTT -- so much so, that I occasionally will fill their tanks with 5 gals of E85 and 15 gallons of 93 to make my own ~E25-30 blend -- the extra octane is immediately noticeable as extra grunt.

I also have an 997TT with upsized injectors and an E85 tune. On E85 it picks up an extra 125 hp due to increased boost, advanced timing, and cooler exhaust temps from running the cooler burning ethanol (which is ~100 octane equivalent). It's basically race fuel for $1.85 a gallon, which easily makes up for the reduced mileage. As a car enthusiast, I like that -- A LOT.

On the flip side, running E85 makes your car smell like a moonshine still -- and I'm not sure I like that -- it's an acquired taste [smell?], but many think it stinks. Also, E85 is harder to find than E10/15 -- so you often have to plan your driving to make sure you can find E85 stations to fill up. On a Flex Fuel vehicle, that's not a concern, but on a modified Porsche, I decided it wasn't worth the risk/ hassle and switched back to running 93octane E10. I must be getting old, because I valued safety and convenience over horsepower and bragging rights...

Apparently the ethanol blends also burn cleaner and keep the combustion chambers and valves cleaner. That also keeps knock sensitive, high compression or turbo engines running better. So as more and more modern cars get [smaller] turbo charged engines, having additional ethanol in your gas may actually improve performance and keep them running better.

But I also get that the lack of choice sucks, particularly for owners of older vehicles that don't benefit (or suffer even) from ethanol's properties. It'd be nice if ethanol free gas was still widely available for those that need/want it.

[sammyg2]

Originally Posted by red-beard

Look at this chart.

Rubber Chemical Resistance, Rubber Chemical Compatibility, Page 3 - Mykin Inc

Butyl and EPDM are fine. But Viton is attacked

Which is problematic, as viton and buna N (nitril) are the most common elastomeric materials used on machinery and are very good with motor oil. Viton is great with gasoline but bad for alcohol. Buna n is Ok with gas and good with oil but bad with ethanol.

EPDM is very good for alcohol but terrible for gasoline and most oils. Swells up and turns to gum.

The last material listed on that chart is Kalrez. Expensive stuff but awesome.
At my last job I spent a quarter mil a year at least on kalrez O-rings. It has nearly the chemical resistance of PTFE and nearly physical properties of a neoprene (but usually a little harder and a little less memory).
It's the go-to when working with strong volatile aromatics.