Let's Get Technical: Ethanol and Gasoline

By Tom Dobush, December 2013

Recently, I have been asked to discuss fuel, a topic which seems to be pretty relevant to most drivers today, even to the many drivers out there that have never given much thought to it, perhaps other than price. You don’t have to be a performance enthusiast to realize that things are changing. The US government has passed laws in the past ten years or so that have changed the regulations concerning the gasoline we burn as fuel in our cars. Over time, especially in the next ten years and beyond, these regulations will continue to change the fuel available at our local gas stations. This article will touch on some pros and cons to this inherent direction we are headed.

As the regulations dictate, fuel available to regular consumers at retail gas stations must contain a percentage of ethanol depending on your region and state. Usually the rating is E10 or E15, which signifies the fuel contains ten or fifteen percent ethanol respectively. This is true for over 95% of gas stations around the country. Ethanol is a refined corn based alcohol type fuel. There are some serious political and economic motivations that have led to the push for the use of ethanol as a fuel additive in this country. Not exactly sure how these motivations came to be, but my best guess from what I have found is that these motivations started back in the good ol’days around the turn of the century when gasoline prices began to increase over the dollar per gallon mark. By 2005 these motivations had become law and have continued to change the fuel we have available to us. In theory, ethanol use reduced the demand for gasoline which in turn reduced the demand for foreign oil for the purpose of stimulating the US economy. This may have helped in the short term but we have yet to see the long term effects.

So far, what many are noticing are some negative side effects of this fuel additive or alternative. For one, engine efficiency is reduced resulting in most vehicles to have lower gas mileage when compared to ethanol free gasoline use. In new cars some of this is counteracted by the higher fuel mileage rating requirements, but none the less the fact remains all cars would have better mileage with the non-ethanol gas. So with reduced mileage per gallon we see more consumption, counterproductive to the goals of the regulations perhaps.

Another side effect is fuel system degradation over time. Vintage and classic car enthusiasts have noticed this more so than those that only have experience with new cars’ fuel systems. Rubber and plastic components react adversely to the ethanol, which increases maintenance costs. Because of the organic nature of the corn based fuel, it also has a natural tendency to attract water, which is public enemy number one when speaking of internal combustion engines and their various types of fuel delivery systems. Water in the fuel system causes corrosion throughout the system ultimately leads to a loss of fuel octane value from phase separation causing higher combustion temperatures and premature or advanced wear inside the engine. Many newer cars have advanced computer control systems to counteract some of these side effects making tiny adjustments to better deal with the poor fuel quality, however the older vintage and classics have simpler fuel systems and less computing power if any at all and therefore need more hands-on adjustment than they used to. Octane boosting additives may help a bit, but only with part of the problem since the water is not eliminated. Even worse for vehicles that get limited use, like most vintage cars I know of, is that the ethanol will separate from the gasoline inside of the tank if allowed to sit for an extended period of time, sometimes as little as two weeks. Fuel stabilizers like Sta-Bil help to reduce the effects but only to some extent. The only way to reduce the negative effects is retune the older engines for reduced power and/or efficiency. Plainly put, any amount of ethanol in your fuel is worse than none. The only way to eliminate these effects is to eliminate the ethanol all together.

Fortunately, there are still some gas stations out there that offer ethanol free gasoline. It seems more have been offering ethanol free as we have become more educated on these side effects and demand has increased. If possible, no matter what you drive, it is in your favor to seek out this ethanol free alternative as often as possible. Of course with high demand and low supply there is a premium in cost, but it is clear that over time the increased fuel cost will be far less than having to replace prematurely worn parts in your engine and fuel system, especially on most vintage or classic vehicles.

A quick google search for ethanol free gasoline should help you find the local gas stations that offer the good stuff in your area; the higher octane the better. I hope this helps to keep your cars running at their best. Maybe if everyone realizes the upside, perhaps demand will increase enough that ethanol free will become more readily available, at least until we all end up driving whirring little electric cars before too soon.

Believe it or not, there is a lot of research out there that shows that the energy used in ethanol production is actually higher than that contained in the fuel itself and it doesn’t burn as clean, so it might not be as good for the environment as we were originally led to believe. Just some food for thought. As always, I greatly appreciate your questions and feedback and can be easily reached at BavarianRocketScience@gmail.com. Thanks for reading and happy motoring!