ethanol
Has any one heard the rumor that they may stop forcing us to buy gas with ethanol in it? I read the program may be stopped. IMOP would be a good thing. Ethanol robs power, hurts MPG, and causes mo...
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I am not going reference any other post or even outside data. What I am going to tell you about experiences in engine testing laboratories that I either worked in or directed during my long career as a lab rat.
Gasahol was proposed during the Carter administration to lessen the demand for imported oil. As much as the amount of oil import has changed, you can understand how successful this program was. (Hint - oil imports are higher than ever)
When a properly maintained engine is tested, the actual emissions difference between fuels was not measurable with the existing technology. There were changes that could be identified with in-stream chemical analysis. This change could also be identified by using a spectral analysis (device made by Nicolet Instrument) that could speciate the specific hydrocarbons in the exhaust. This is a seriously moot point as all the exhaust gasses will pass thought an oxidizing catalyst before leaving. We though about it a while, and when we got a vehicle (often out of the employee lot) that we new was in poor tune for the fuel test, we cold measure a change. That change was usually for the better, but not always. These tests were done with both open loop and closed loop engines and tested in many different methods. If the subject engine was closed loop (has an oxygen sensor in the exhaust) then the change was hard to see, and as soon as the fleet was largely electronic fuel injection, that change was not detectable by any means.
At the time it was proposed, those of us that were technically smart about engines were aware of the problems this could cause, but none of us were really ready for the damage this would do to the existing fleet.
As it happens, some years back we acquired a classic vehicle. This vehicle is not just pre-cat, but is open loop and the only computer onboard is what we use for navigation. When we started useing her for travel (and being a dyed in the wool lab rat along with both an aircraft pilot and a lifelong watermen) I took up carefully logging fuel consumption. I got with a chemist friend and we developed a simple and carry-able method to quantify the amount of alcohol in the motorfuel we took on. It did lack accuracy when compared to the lab tests, but was convenient to carry and it was accurate enough. I had originally planned to reject fuels that had ethanol, but that turned out to be impractical. But I did log the measured concentrations in my fuel log. It only took a few thousand miles for some trends to be confirmed. The final result was relatively clear. The alcohol behaved like a filler. If we went from no alcohol to full 10% at similar altitude, the change would be exactly the alcohol. So, sea level to about 3000ft (east of the Mississippi) the change in fuel consumption would be almost exactly the alcohol. That means if the fuel was a full ten percent, the coach mileage would go down that same ten percent. The engine was (and still is) tuned for sea level, and in later log entries at higher altitude the difference seemed to have been less, but I had lost interest at that time. The doctored fuel did exhibit exactly the same knock resistance as those fuels that were not doctored, but all motor fuel has been shipped a rating by average of motor and research octane numbers, so that is to be expected.
One thing I had not counted on was the damage that modern "motor fuel" would do to an old fuel system. In the time I have owned this, I have had to replace everything that was not tern plated steel. There are Rochester kits that now have specific ethanol resistant components. There are rubber fuel lines that claim a ten year life.
Did you wonder what happened to 15%? When it was mentioned, the majors all included parts in the fuel system that would indicate that 15% fuel had been used. If that part indicated that it was, all warranty and safety guarantees would be void. There is a big reason why a "FlexFuel" costs more.
I should not have this much time to write here, but I am in SE MI and the outside temperature is brutal.
Matt
Gasahol was proposed during the Carter administration to lessen the demand for imported oil. As much as the amount of oil import has changed, you can understand how successful this program was. (Hint - oil imports are higher than ever)
When a properly maintained engine is tested, the actual emissions difference between fuels was not measurable with the existing technology. There were changes that could be identified with in-stream chemical analysis. This change could also be identified by using a spectral analysis (device made by Nicolet Instrument) that could speciate the specific hydrocarbons in the exhaust. This is a seriously moot point as all the exhaust gasses will pass thought an oxidizing catalyst before leaving. We though about it a while, and when we got a vehicle (often out of the employee lot) that we new was in poor tune for the fuel test, we cold measure a change. That change was usually for the better, but not always. These tests were done with both open loop and closed loop engines and tested in many different methods. If the subject engine was closed loop (has an oxygen sensor in the exhaust) then the change was hard to see, and as soon as the fleet was largely electronic fuel injection, that change was not detectable by any means.
At the time it was proposed, those of us that were technically smart about engines were aware of the problems this could cause, but none of us were really ready for the damage this would do to the existing fleet.
As it happens, some years back we acquired a classic vehicle. This vehicle is not just pre-cat, but is open loop and the only computer onboard is what we use for navigation. When we started useing her for travel (and being a dyed in the wool lab rat along with both an aircraft pilot and a lifelong watermen) I took up carefully logging fuel consumption. I got with a chemist friend and we developed a simple and carry-able method to quantify the amount of alcohol in the motorfuel we took on. It did lack accuracy when compared to the lab tests, but was convenient to carry and it was accurate enough. I had originally planned to reject fuels that had ethanol, but that turned out to be impractical. But I did log the measured concentrations in my fuel log. It only took a few thousand miles for some trends to be confirmed. The final result was relatively clear. The alcohol behaved like a filler. If we went from no alcohol to full 10% at similar altitude, the change would be exactly the alcohol. So, sea level to about 3000ft (east of the Mississippi) the change in fuel consumption would be almost exactly the alcohol. That means if the fuel was a full ten percent, the coach mileage would go down that same ten percent. The engine was (and still is) tuned for sea level, and in later log entries at higher altitude the difference seemed to have been less, but I had lost interest at that time. The doctored fuel did exhibit exactly the same knock resistance as those fuels that were not doctored, but all motor fuel has been shipped a rating by average of motor and research octane numbers, so that is to be expected.
One thing I had not counted on was the damage that modern "motor fuel" would do to an old fuel system. In the time I have owned this, I have had to replace everything that was not tern plated steel. There are Rochester kits that now have specific ethanol resistant components. There are rubber fuel lines that claim a ten year life.
Did you wonder what happened to 15%? When it was mentioned, the majors all included parts in the fuel system that would indicate that 15% fuel had been used. If that part indicated that it was, all warranty and safety guarantees would be void. There is a big reason why a "FlexFuel" costs more.
I should not have this much time to write here, but I am in SE MI and the outside temperature is brutal.
Matt
