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Please keep us posted! I'm really interested to see how this experiment turns out.

Quote:
I needed gas this morning going to work. I usually get Shell 92 with 10% ethanol at Circle K because they have good coffee. Right now Shell 92 with 10% ethanol is $3.62.9/gal.



Well, their pumps weren't working and they didn't seem to be in any hurry to fix them, so I drove down the road to Greg's Gas Plus, one of the better, cleaner, generic convenience stores that sells a lot of gas. The pump that I pulled into in my low-caffeine daze turned out to have only 93 octane ethanol free gas, for $3.85.9/gal. So, I filled up the BMW 335xi, got some coffee (which sucked) and hit the road. Oh, first I cleared the BMW's trip computer, which showed that I had been averaging 25.7 mpg in a 10% city, 40% 2 lane blacktop, and 50% Interstate cycle. This trip computer has been very close to real data over the 2 years I have had the car.



$3.629/25.7 mpg = 14.1 cents per mile



I drove the remaining 32 miles to work on 2 lane blacktop, 45 to 65 mph. When I got to work, the trip computer said I was getting 34.5 mpg.



$3.859/34.5 mpg = 11.2 cents per mile



Since I drive about 100 miles a day, I go through a full tank in 4 days. I plan on using only ethanol free for the next couple of weeks, then I will post my mpg comparison.
Old 05-21-2012, 05:10 AM
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Quote:
Originally Posted by tirwin View Post
Please keep us posted! I'm really interested to see how this experiment turns out.
I'll be interested in your findings, on a recent long trip in my 328i I experienced the same thing (fairly large disparities in fuel economy). I filled on the road without having much of a choice and found only premium blends, but in the city I started in and the destination city, I filled with premium (no ethanol) and found a significant increase. Cheers
Old 05-21-2012, 05:32 AM
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Here is the BMW dealer who found ethanol content was much higher as discussed on another forum.

87 vs 91 octane - Page 6 - Hyundai Genesis Forum
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Old 05-21-2012, 06:06 AM
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Ethanol contains 28% less energy than gasoline, so effectively e15 has 4.2% lower energy contant than 100% gasoline. so a car that gets 25 mpg would get roughly 24 mpg using e15 vs. 100% gasoline

I'm not really on one side or the other on this subject...

A) I don't trust government reports that suggest e15 is SOOO much better than 100% gasoline. I think in terms of tailpipe emissions you see minimal at best improvement.

B) I don't trust reports funded by the auto industry on e15, they have to increase average MPG of their lineups 1mpg can be the difference between paying huge fines for them

In my experience with ethanol (E85 on my Turbo Saab) I loved it! From a performance stand point it was awesome (110 effective octane rating), it burns cooler, I could increase boost a shizz ton, I was able to run more timing without knock.

In the end I got about 4 mpg worse gas mileage or about a 15% reduction. but e85 was about 15% cheaper anyways so overall fuel costs where about the same

I ran E85 for about 2 years before I blew the transmission up in that car and got rid of it, never replaced a fuel line, never hurt my walbro 255, and the motor was pulling strong with 178K miles and had never been rebuilt... So yeah I'll covert my next turbo car to e85 as well

So yeah I like ethanol and turbos!
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Old 05-21-2012, 06:56 AM
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So from your testing one can assume that in markets other than yours, E10 is more like E20-E30 as people generally report more than a 1mpg hit when compared to 100% gas.
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Old 05-21-2012, 11:17 AM
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e-15

Lets get real ON THIS ISSUE !

WE have ethanol in our gas because of the gov't and initial feelings that it" seemed
to be harmless and would(or might) assist in benefits in mileage". Unfortunately both proved wrong.
The gov't let the 6 billion subsidy we paid to the corn guys expire and (unfortunately it did nothing . .

Now we pay for the expired subsidy at the pump DIRECTLY- not as part of a subsidy.
A manifestation of the zero- sum game we have become so used to.

Now we're told we need a 15% ethanol content which hurts older engines and may or may not hurt newer engines(it has been proven to hurt the older ones). This is the hamburger helper of the early 2000's were asked th swallow.

Next please!
Old 05-21-2012, 01:10 PM
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Ethanol in gas is really not so bad as long as the gas is fresh. Well besides the increase in food prices - the increased cost of making ethanol out of corn - the inefficienceis compared to lots of other

If significant amounts of water are present in a fuel tank with gasoline that contains ethanol, the water will be drawn into the fuel until the saturation point is reached for the three-component mixture of water + gasoline + ethanol. Beyond this level of water, phase separation could cause most of the ethanol and water to separate from the bulk fuel and drop to the bottom of the tank, leaving gasoline with a significantly reduced level of ethanol in the upper phase. If the lower phase of water and ethanol is large enough to reach the fuel inlet, (as in the feed to the fuel pump in a 1976-1989 Porsche 911) it could be pumped directly to the engine and cause significant problems. Even if the ethanol water phase at the bottom of the tank is not drawn into the fuel inlet, the reduced ethanol level of the fuel reduces the octane rating by as much as 3 octane numbers, which could result in engine problems especially in Porsche engines such as the 3.0 and 3.2 that do not have knock sensors.

The level at which phase separation can occur is determined by a number of variables, including the amount of ethanol, the composition of the fuel, the temperature of the environment and the presence of contaminants. It is very important (A) that the system is inspected for significant quantities of water in the tank before using gasoline with ethanol and (B) to limit exposure of the fuel tank to excess water. If phase separation has occurred, it is necessary to completely remove all free water from the system and replace the fuel before continuing operation. Otherwise, engine problems could occur.

Does ethanol affect horsepower or fuel-efficiency?
Ethanol has a heating value of 76,000 BTU per gallon, which is approximately 30 percent less than gasoline's heating value (which is approximately 109,000 to 119,000 BTU/gal). The result is E-10 gasoline should yield slightly lower mileage ? a decrease of approximately 3 percent. Fuels containing higher levels of ethanol will have a corresponding reduction in mileage. For example, E85 fuels produce mileage approximately 30 percent less than gasoline.

What are the characteristics of ethanol?
Ethanol is an oxygenated hydrocarbon compound that has a high octane rating and therefore is useful in increasing the octane level of unleaded gasoline. The EPA, the agency responsible for setting some of the requirements for all gasoline used in the U.S., has allowed the use of ethanol in gasoline at levels up to 10 percent as an octane enhancer and as an oxygenate to provide beneficial clean-burning combustion characteristics that help improve some emissions.

Ethanol is hygroscopic (it has an attraction for water) and will more readily mix with water than with gasoline. It has different solvency behaviors than does gasoline, which allows it to loosen rust and debris that might lay undisturbed in fuel systems. And it can more readily remove plasticizers and resins from certain plastic materials that might not be affected by gasoline alone. Loose debris will plug filters and can interfere with engine operation. Additionally, ethanol is corrosive to some metals, especially in combination with water. Although gasoline does not conduct electricity well, ethanol has an appreciable capability to conduct electricity and therefore can promote galvanic corrosion.

Two Stroke Engines

Phase Separation in ethanol-blended gasoline, however, can be more damaging than in MTBE blends and straight gasoline. When phase separation occurs in an ethanol blended gasoline, the water will actually begin to remove the ethanol from the gasoline. Therefore, the second phase which can occur in ethanol blends contains both ethanol and water, as opposed to just water in MTBE blends and conventional gasoline. In the case of two-stroke engines, this water-ethanol phase will compete with the blended oil for bonding to the metal engine parts. Therefore, the engine will not have enough lubrication, and engine damage may result.

This, while not Porsche specific has been a boon to the two stroke repair market. Think boats, lawn equipment, etc...
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Old 05-21-2012, 05:21 PM
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Ya know... In this country we talk a lot about reducing our dependency on fossil fuels. We've been talking about it since the '70s. As a kid of the '70s I have some memories of the energy crisis. But here we are almost 40 years later (Read that again. 40.) and what do we have to show for it? My dad drove a VW Rabbit diesel in those days. It got pretty close to what most "green" cars get today in terms of gas mileage. We have come so far. If the car industry innovated like the Internet during that time, I would be driving around like George Jetson today.

A few years ago, I made a spreadsheet to calculate the total cost of ownership of a hybrid. For me and my driving, the cost of owning a hybrid never paid for itself. Call me crazy, but it seems like if it could have been done, it would have been done by now. Yet, we keep chasing some elusive holy grail of gas mileage.

I still don't get hydrogen cells. Last time I checked, hydrogen doesn't exist without being bonded to some other atom (except in stars) so you have to USE energy to separate the hydrogen from other stuff. How does that idea work again?

So, I have to wonder... Are there people trying to artificially create a market now? It seems to me there isn't a huge amount of benefit to increasing the amount of ethanol in gasoline. So why pursue it?

Let's say for grins that 10% is ok. Heck, let's say 15% is ok. Why not 20%, 50% or 100%?

My point is that engineers design with a certain set of assumptions in mindvand while I'm not an ME or ChemE or a time traveller, I find it hard to believe that 30 or 40 years ago the engineers at Porsche were thinking about such things.

And if it happens that running something like E85 doesn't cause appreciable harm to my engine -- fine. I'm happy.

All I'm saying is that these old cars are pretty darn cool and it would be a real shame if those of us who enjoy them have to end up paying extra for us to be able to continue to enjoy them. I hope one day I'll be able to drive my grand kids around in the ol' 911 without having to trade in some Unobtanium.

I was watching Chasing Classic Cars yesterday morning. I am still in awe of some of the engineering that went into some cars that are almost 100 years old now. And some of them are real works of art. I just can't see someone looking at a Tesla or a Smart car in the same way 100 years from now.
Old 05-21-2012, 07:30 PM
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I see a few people have alluded to the differences in diesels, but diesel fuel in most places now are 20% bio. And they have had huge problems with freezing and gumming up fuel systems.
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Old 05-21-2012, 08:26 PM
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Originally Posted by manbridge 74 View Post
So from your testing one can assume that in markets other than yours, E10 is more like E20-E30 as people generally report more than a 1mpg hit when compared to 100% gas.
I assume that people exaggerate Fact of the matter is if your sneaky gas stations where using e20-e30 (which would be illegal if they disclosed it as e15) you still wouldn't see these huge differences in MPG, e20 would contain 5.2% less energy than straight gas, and e30 would contain 8.4% less energy

So if you car gets 30mpg, on e20 it would get 1.56 mpg's less, and e30 would be 2.52 less mpg

Math doesn't lie, people do... all the time

But as I said previously I don't give a shizz enough to complain one way or anything. I have more important things in my life to have time to worry if the gas station is ripping me off of 2.8-4.2 % energy potential in my gasoline because the goverment believes that will reduce emissions

I only care about ethanol from a performance aspect, it makes my turbo cars run better in the summer than any other fuel commercially available to me at the pump
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Old 05-21-2012, 08:44 PM
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Quote:
Originally Posted by mfyoung1086 View Post
I assume that people exaggerate Fact of the matter is if your sneaky gas stations where using e20-e30 (which would be illegal if they disclosed it as e15) you still wouldn't see these huge differences in MPG, e20 would contain 5.2% less energy than straight gas, and e30 would contain 8.4% less energy

So if you car gets 30mpg, on e20 it would get 1.56 mpg's less, and e30 would be 2.52 less mpg

Math doesn't lie, people do... all the time

But as I said previously I don't give a shizz enough to complain one way or anything. I have more important things in my life to have time to worry if the gas station is ripping me off of 2.8-4.2 % energy potential in my gasoline because the goverment believes that will reduce emissions

I only care about ethanol from a performance aspect, it makes my turbo cars run better in the summer than any other fuel commercially available to me at the pump
The only thing worse than a blatant statement on ye interwebz is lack of follow-up. Here is mine.....

I had to drive 1000 miles away to visit family before I found ethanol free fuel. And you are right as far as the fuel I bought. About 1 mpg difference assuming the gas I bought was ethanol free as I didn't test.

Still I am considering an ethanol removal procedure for those that would prefer it.
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Old 05-28-2012, 11:45 AM
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Only 5 pure gas stations in California. All hundreds of miles away from me. We are doomed!
Old 05-28-2012, 03:53 PM
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you can convert most small aircraft to run auto gas but the FAA restricts that to non ethanol 89 min. octane fuel only. So i think that fuel will be around for a while
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Old 05-28-2012, 09:37 PM
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The only thing worse than a blatant statement on ye interwebz is lack of follow-up. Here is mine.....

I had to drive 1000 miles away to visit family before I found ethanol free fuel. And you are right as far as the fuel I bought. About 1 mpg difference assuming the gas I bought was ethanol free as I didn't test.

Still I am considering an ethanol removal procedure for those that would prefer it.
Its not really a blatent statement its called math, I do not feel the need to go real world test gas mileage differences to prove a simple simple calculation correct...

But if you want my real world testing I'll give you this. I work in Saudi Arabia, where gas is not mixed with ethanol, my exploder gets 15.3 MPG sooo I'm not really seeing it getting 8 more MPG's (or whatever exaggerated number ppl come up with) cuz I'm running straight gas, and it doesn't run better than a normal exploder, and it's not faster than a normal one (which is actually kinda sad cuz this thing is piss slow for a 4.0L)
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Old 05-29-2012, 04:13 AM
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Update on using "93 octane ethanol free" for 3 full tanks in my BMW 335xi.

In post #40 I said right after filling up with this stuff, my trip computer said I was getting 34.5 mpg, versus the 25.7 mpg it normally gets on 92 octane with 10% ethanol. Unfortunately, that didn't last once I got off the low speed 2 lane blacktops, and after about 1200 miles, the new calculation (confirmed with calculator) is right at 27.0 mpg.

Still it's an increase of 5% in milage, for approximately 5% more in cost, so I broke even. And the price of 93 octane ethanol free had dropped to $3.699 this morning.

I really couldn't tell any difference in power, but this damn car is so twitchy and powerful anyway (stock but with BMW Performance Power I upgrade) that I don't usually drive it hard. But if using ethanol free may keep it from having some expensive repairs to the fuel system (it's already had the DMTL pump replaced 4 times under warranty) then I'll keep using it as much as possible.
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Old 05-29-2012, 06:08 AM
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