ethanol % and plastic gas tank issues
 

HI, I have been searching for a few answers for a while and seems that I cant find the answer. Over the past few years I have read and watched videos over the internet. I do not know anybody around me who is somewhat real specialist or scientist that can tell me so I have no other source of information rather than the internet
I know in most gas stations on the fuel pump says “contain up to 10% ethanol” and on some says “contain 10% ethanol”

Some gas stations has individual nozzle for each type of gas (87 89 91 etc)
But many, including the one I use on a daily bases have only 1 nozzle for all the octanes.

--->My first question is: How come 1 nozzle can dispense 3 different octane ratings? Is there a mixing device in the pump that can mix different ratio of fluids into the desire gas? And if so is this ethanol and pure gas mixture or what approximately it is.

I have 6 cars with different engines and all of them perform different to the different type of fuels. Many engine types means different results so one shoe dont fit all. So for me is very important to have the clear picture of gas content and ingredients to make my informed choice.
The old Audi 1995 A6 has engine that is supposed to run on 91 and up octane but I have on few occasions made test. With pretty empty tank I filled up different fuels. The 93 octane runs great but I was surprised to find out that on 89 octane my car ran very and seemed some how with tiny bit of more power. Usually the concept for german cars is vice versa.
The 2010 VW 2.0liter 4 cyl Turbo engine we have and my old sold 1999 BMW 528i non turbo 6 cyl, felt the difference immediately. When I put 87 octane those cars are pretty weak. When I put 93 the performance is significantly better.
My other cars I drive are/were 2015 Lincoln mkT 3.7 V6 non turbo. That car runs like a champ on any fuel. The new one is 2018 Lincoln MkT with 3.5 eco boost turbo engine and I have drove so far for 2 weeks ownership only on the regular but will soon go to try premium.

The cherry of the cacke is my 1997 Audi cabriolet which has the same exact engine as the 1995 Audi A6 and the main problem I have there is the car has gas tank 100% made of plastic. The structure of the car made them put the gas tank in behind the store for the roof. Few guys with that car have had fuel fumes coming from the top of the tank and now I have the same in the trunk. One of the guys is an experienced german car mechanic and he said this is due to the ethanol that deteriorated some of the very specific top part of the gas tank.
Few years back I lived down south and were able to put 91 ethanol free gas at my local gas station. Now I live in Chicago and the ethanol free gas is like 120 miles away.

--->So my second question is: Which grade of gasoline will have least ethanol content in it. For the other cars – I don’t care as long as the run, but for the Cabriolet I want to put as less ethanol in this car as I can. I know many gas station will for sure have different recipes for gas but maybe is similar
Thank you

First, the pump. Refineries deliver regular and premium octanes to the stations, and a blander pump will mix those to get the in between octanes. Stations without them have another tank in which the delivery truck mixes regular and premium for midgrade.

As to what gas has ethanol, there really isn't an easy way for American consumers to find out. It varies between, and even within, states. You can try looking up your state regulations concerning gas formulations, but it likely all has ethanol near major cities. Have you tried Pure-gas.org? You might be able to find a shop selling high octane, ethanol free race fuel by the jug nearer to you. The price will be $8 to $10 a gallon, but might be worth it for a limitedly used car.

That said, ethanol may not be the issue. Yes, plastics last a long time, and pose an environmental issue, but they don't remain just like new chemically during their life. Part of the environmental issue is the chemicals they break down into and leach out. Gasohol was being used during the oil embargo. A car from the '90s should have been made to handle 5% to 10% ethanol. I suspect being over 20 years has more to do with the tank breaking down than the ethanol alone.

Thank you
I have and keep looking at pure-gas website. THere are some race fuels and airports that sell ethanol free fuel nut i dont know how good it will be for the car to put the 100 octane airport gas. The car can handle 10% ethanol obviously but dont like it that much for the gas tank.
When i do long trips i get some gas containers and fill up ethanol free gas for example from Indiana.

as for the gas stations: I thought the gas station and some animation of how it works, they have only 1 big gas tank container underground and few small ones like for ethanol for example.

As you have said the pump mixes it. So if lets say the Shell gas station nearby sells 87 89 and 93, which of the fuels is likely to have the more% ethanol? the 93? I know ethanol has like 30% less energy but this is not 30% less octane as octane number doesn necessarily mean more power?

I think, and hope, the practice has stopped, but piston aircraft gas was still using lead until recently. Seeing how NASCAR only recently stopped using lead, the race fuels might still have it.

Ethanol can't be pumped through our current petroleum pipe lines, so gets mixed in at the distribution tanks, or the delivery trucks themselves. The ethanol getting mixed in isn't pure ethanol; it has been denatured with 2 to 3 percent gasoline at the plant. In theory, a station selling E85 could get pure gasoline and mix in the 10% ethanol, but that is not likely.

With the ethanol mandate, and potential of regional regulations, it isn't possible to say how much ethanol is in each octane rating for most people. I believe Canada dictates that premium be ethanol free for example. 89 AKI is a 10:2 mix of regular and premium, so the midgrade there will still be close to E10. I live near NJ and Philadelphia, so I just assume everything is E10 here. I think there are test kits that measure the ethanol content of gas, but your station's fuel formula will change with the seasons, and could change with the supplier.

Ethanol has an effective octane rating of 105, and was used as an octane booster in some markets before the ethanol mandate. Octane is a measure of resistance the gasoline is to ignition from high pressure. The higher the octane, the higher the compression ratio the engine could have, which lets more of the chemical energy in the gas be converted to mechanical energy. Historically, that fact was used to generate more power out of the engine, but it can also be used to improve efficiency.

That kind of suggests that the lower the octane rating the more likely there is to be less ethanol.

I have one very small glass jar that measures the % (up to 10%) and actually you can measure the ethanol without precise percentage with a regular glass jar on which you can let say compare different gas if you put the same amount of water.

I also know that some gas stations will receive the E10 and put another some% of theanol.
I am far from the idea that all thousands of gas stations and tens thousands pumps are accurate of the mixtures

Here in Canada the only gas station that actually puts the ethanol content on their pumps is Ultramar, so I try to fill up at their station as often as I can. Both the car and the bike use 91 octane, so the less ethanol there is in it the better for me. I would assume that the ethanol is mostly placed in lower octanes, since most of the expensive engines are designed to run on 91 and higher octane without ethanol. There are rumors that car manufacturers want to go to one fuel in 5 years with a 95 octane in North America. There are some places in Ontario where you can get 93 octane, but most of the country is limited to 87 - 89 - 91. My bike and car is designed to run on 93, but 91 will have to do for now.

Toluene and xylene are two other common octane boosters in gasoline; their effective octane ratings are 121 and 118. I need to add that those, and ethanol's 105, values are RON.

Because of the ethanol mandate, the regular grade gas made at the refinery might be 87 now.

This works because of the phase separation that occurs with the excess water.

There is variation between pumps, but they have to conform to standards testing with legal penalties if they don't. Fraud aside, they all should be close.

Premium is typically 93 in the US. Except in California, and maybe other CARB states, where it is 91. Some stations offer higher.

Those are AKI values. The average of RON and MON, which are the results from two different octane tests. That is the first I've heard of the car companies wanting to go to one octane, but have heard of them wanting a higher regular and switching to RON from AKI. Which is a good idea.

The RON test is the better predictor of the fuel's behavior in a fuel injected engine of the two. Higher octane regular would allow squeezing out a little more efficiency from the engine. It would also bring American regular gas in line to what most of the world specs for regular gas; making engine development cheaper. Note that a 95 RON gas is likely 90 AKI, so not a large change from what we have now.

Changing the gas formula isn't a real big deal. We recently phased in gas with even lower sulfur content in order for cars to comply with the new US Tier 3 emission regulations. The gasoline the first cars burned had an octane in the sixties, and contained more of the nasty stuff, like benzene.

On another note, using pure gas to describe gasoline without ethanol is a misnomer. Gasoline is not a single compound. It is a mix of different ones that vary between the source petroleum, the refinery, and what regulations are in effect. Many here know of the changes between summer and winter, but the gas found in major metropolitan areas is formulated to be cleaner in emissions than the gas out in the places with lower population density. Part of the reason for California's relatively high gas prices is that CARB has their own gas formula requirements.

Gasoline is like fruit punch. The exact juices that go into the punch vary between recipes, but they are all fruity tasting sugar water in the end.

Go to pure-gas.org
They list ~ 13,500 sources in Canada & U.S. with ethanol-free gasoline(E0). Sounds like a lot of stations, but often people have no E0 sources near them. Many states have no E0 or very very little E0. That is how effective the "ethanol in gasoline industry" has manipulated the EPA to stuff ethanol in gasoline(E10). Even if you can find E0, it is often $1 per gallon higher in price than E!0, again since EPA penalizes oil companies for supplying real gasoline(E0).

Gas pump labels only say up to 10% ethanol. They aren't required to state the exact amount, or if even one of the octanes is ethanol free. Pure-gas.org relies on user reports for sources of E0. So it comes down to what the station is reporting.

Some just want to know if they are getting less than that 10%, as is the case here, and some want more. I really wanted to try E30 in my Ranger when I had it.

The only E0 sources not out of my way are high octane racing fuels sold by the jug, starting at $8 a gallon the last time I checked.

Knock sensors can make a big difference in the performance "feel" of an engine. Not sure about the later VWs, but the knock sensor system from the 1985-1988? A-2 Chassis GTI and GLI worked by constantly advancing the ignition timing like 1° at a time until the knock sensor picked up detonation, then it would instantly retard the timing like 3° and start the cycle again. In theory the better the fuel, the more advance you'd get and at a faster rate. I used to swap that system into low compression (8.5 to 1) engines and that change alone would make a big difference in the "feel" of the car. Not sure about the later systems, but a bad knock sensor (the mounting bolt torque was critical) would take that all back, especially if it was bad enough to trigger limp home mode. If memory serves me right, Chevron or Shell gas gave the best "feel".

In Florida, ethanol free fuel is pretty easy to find and in my area usually less than $1 extra.

I can't see ethanol eating away the plastic body of the fuel tank. I can see it ruining an O ring for the sender or eating away a rubber vent hose.

As I said, the plastic is like just old. Picked up an older disposable food container, and it shattered with a light squeeze.