Recently, I noticed that the gas station I am going to is offering a premium blend gasoline with no ethanol added. So, my question is whether or not that gas is worth it or not. So, I have to do some research about this concerning the pros and cons. I know that many have strong views about this; some use this as a reason why the government is taking over our lives. I wish to answer some questions and answer that question in the end.
As a chemist, I look up in my books and find that E0 gas, burnt in lab, measured out to have about 115 kBTU/gal versus the popular E10 blend gas at about 75 kBTU/gal. It means that there is a potential energy output of gasoline that is about 1.5 times as great as ethanol. So, with E10, I expected a 5% improvement. If I was getting a MPG of 15 that it would increase to 15.8. One can say this is a drop in the bucket. The problem by my observation in my vehicles is this does not equal a comparable increase as the MPG. Or, the benefit maybe not even be noticed at all. I noticed inconclusive results in my truck mainly due to its low MPG as predicted.
With my experiment, I went on the same day noting all atmospheric changes did not change. Then after filling up I drove about 250 miles. I used the same pump and stopped at the second auto shutoff. I tested other vehicles with larger MPG. My motorcycle actually showed a decrease in MPG by about three MPG. Yes, it is a Harley Davidson and I do not know if the ECM can adjust. Ethanol does not need as much oxygen to burn. My mother’s Prius also did not change perhaps because of its heavy feedback system. My brother’s older car, a 2004 Pontiac, did show a highway increase by about three points going from 22 to 25 MPG. It seemed that urban driving had inconclusive results. One must understand that the rather informal testing that I performed had an error of about 2%. I ran about five tests, averaged the results and assessed the error. At best, I might get a three percent increase which could be overshadowed by the efficiency of my vehicle’s combustion system. Still, the question remains whether or not it is worth it.
While some, including myself, do see even a slight increase in MPG. The problem is that at the gas station the E0 gas remains most expensive as premium blend gas. For me and my vehicles, this does not work to my advantage; it is just too expensive. Currently, the gas sells at 3.239 per gallon-- the octane 87 for 2.849, the octane 89 for 2.979, and octane 91 for 3.109. The premium E0 is 4.1% more than the E!0 premium which means it eclipses any benefit as discussed above. And keep in mind that the engine has to struggle to get a 3% MPG increase. I can see older cars may benefit including those that have a carburetor. And, now I test the same vehicles with the octane ranges. Basically, I see the same results with the higher octane with a 3% MPG increase. The MPG seems to decrease with the lower octanes. I can say the high octane gas gives me as good a MPG improvement. Could this be what some testers are seeing? Maybe with the E0, the same additives are left in the gas to not have “pure” gasoline. Perhaps that low octane gas, and the mid-range gas seemed to be boastful of its octane, is crap and functions like it is lower. I definitely decided after my tests to run exclusively the premium blend.
Then, as a chemist, I know that some engines may not take the ethanol gas. Most people I talked about the awful result of putting the E0 in small engines. There is no doubt that marine engines suffer as the combustion is more acidic and destroys the engine. Does this translate to cars? In cars, as ethanol does burn cleaner and help remove water and dirt, the exhaust must be removed. This means cars need more robust exhaust systems which could by themselves; and, any mechanic will say a lame exhaust system can affect MPG. Maybe some cheaper cars with plastic based engines would be in the similar boat as the small engines.
Still, a mechanic friend showed me six cylinder blocks—one disassembled that used the E10 gas and another showing E0 gas bought in Iowa. I could see the E0 block was quite black with soot. The E10 engine had a little black; but, that engine block was still metallic shiny. If one used the E0, seals would be the least worry as the valves get blackened and stick lowering engine efficiency. The ECM would compensate by increasing base RPM to handle the inconsistent engine RPMs used to drive the transmission. That increase would nullify any MPG benefit. So, the E0 user would need to more frequently clean everything in the engine. The corrosive nature of alcohol is a concern; however, I see no real benefit with my vehicles use E0 as when E10 seems to be better at keeping my engine clean.
One can go online and see both environmental and political pros and cons. Many people swear that the burning of ethanol is better for the environment. The production of the ethanol from the growing of corn to the fermentation and distribution of alcohol is more hurtful to the environment. The truth of the matter is that internal combustion in general is bad to the environment; it is basically an open system that destroys its fuel. If one uses the fuel it is gone. It cannot be renewed. It is important to develop some renewable energy method for our vehicles. These renewable have to be done in such a way as to make sure the environment is protected, that there still is a potential to make money, and is affordable to the population. The realization is that industry is not good for the environment; but, there are systems to keep emissions low. Soon, I hope this renewable source will become the choice.
Finally, there are political concerns. And, some are very supportive of their choice. The safe answer to the headline question is that it depends. But, from my experimentation and research I find I cannot use E85 or pure alcohol. I also see that there is no real benefit from using the E0 gas. E10 gas is just fine. The benefit for farmers will continue to exist and our food supply will not be affected. And, still there are people who wish to use E0 no matter what. That is there choice and in our country choice is good.
This article lays out the pros and cons very well
Article talking about small engines.
Post showing some details about ethanol
Check out this discussion about the pros and cons of ethanol.