Q: Does ethanol clog fuel filters?
A: In early test trials, ethanol was put into older vehicles with fuel systems that had become varnished during normal use with gasoline. Varnish generally only accumulates in fuel systems or containers which see little or no use. Ethanol removes this varnish from the tanks, fuel lines, and carburetors which is then captured by the fuel filter. Once the fuel system was clean and the filter replaced, this issue was resolved. Today’s gasolines contain detergents which help keep fuel systems cleaner and, in most cases, when ethanol fuel is added to a clean fuel system, there is little (if any) varnish in the fuel system and filters are less likely to become clogged.
Q: Is the ethanol myth true that ethanol is bad for
certain gasoline fuel system components, fuel pumps and carburetors?
A: Early versions of some elastomers (rubber-like parts) and metal fuel system components were subject to deterioration over time; manufacturers quickly began to change these fuel system components to be compatible with ethanol fuel. From time to time, this myth enjoys circulation, but it is not true. Today, all vehicle manufacturers, domestic and foreign, approve* the use of ethanol fuels.
Q: Does the use of ethanol-blended fuel cause a decrease in fuel mileage?
A: There are many variables that contribute to fuel mileage, such as the season, the weather, and traffic conditions, that only an average miles per gallon can be determined. Current information derived from controlled environmental testing suggests that fuel injected vehicles may experience a decrease in mileage by approximately 2%. A carbureted vehicle that averages 30 MPG on the highway might average 29.4 MPG using ethanol-blended fuel; a small price to pay for a cleaner environment.
Q: Will ethanol-blended fuel attract moisture to my fuel system?
A: All of today’s automotive fuel systems are closed systems and are less prone to attracting moisture. Ethanol absorbs moisture that is in a fuel system and carries it out in suspension as it is consumed. The most likely, and quite rare, cause for water in gasoline today would be from condensation in service station storage tanks. If the concentration of water in ethanol becomes excessive, it will separate and fall to the bottom of the fuel tank. When ethanol fuel is used in winter months, a fuel de-icer is not required.
Q: Does ethanol plug fuel injectors?
A: Earlier fuel injectors of the pintle design could form deposits that changed the pattern of the injected fuel. This problem developed from injectors seeping fuel when the vehicle was not running. This formed carbon deposits on the pintle and caused even more leakage. This could happen with any gasoline. Because of this problem, injectors in most vehicles have been re-designed around the popet style and all gasoline is required to carry a detergent component to alleviate the deposit problem.
Q: Does ethanol use cause injector failure?
Q: Isn’t ethanol fuel blended to over 10% many times?
A: This seemed to be a problem on certain vehicles from 1988 to 1993. The manufacturers changed the injector coil insulation on later models and resolved the issue.
A: Over blends of oxygenates in gasoline are rare and never intentional. Ethanol, MTBE and other ethers all cost significantly more than gasoline. To over blend even 2% results in increased production costs exceeding 1¢ per gallon. Manufacturers of oxygenated gasolines are very cautious not to over blend and most now use very sophisticated equipment to achieve precise blend levels at or below maximum permitted levels.*
Q: Does ethanol cause vapor lock on hot days?
A: Today, fuel vapor pressure is regulated by the EPA with a lower vapor pressure for summer grades of fuel. In the Midwest, ethanol fuel may carry a one pound higher vapor pressure than conventional gasoline. Occasionally, a vehicle may vapor lock on a hot day, but this problem has mostly been eliminated.*
Q: Will we deplete human and animal food supplies by using corn and other grains for fuel production?
A: No, actually the production of ethanol from corn uses only the starch of the corn kernel. All of the valuable protein, minerals and nutrients remain. One bushel of corn produces about 2.7 gallons of ethanol, 11.4 pounds of gluten feed (20% protein), 3 pounds of gluten meal (60% protein) and 1.6 pounds of corn oil. Bt-corn is a genetically modified version of corn which has been studied for use in foods and as a renewable fuel resource.
Q: Does it take more energy to produce a gallon of ethanol than the energy we get out of it?
A: No. Research indicates an approximate 67% gain in the overall corn-to-ethanol process and use of that ethanol for fuel. Corn yields and processing technologies have improved significantly over the past 20 years and they continue to do so, making ethanol production much less energy intensive.
- A 10% ethanol-blended fuel is warranted for use by ALL auto manufacturers marketing vehicles in the U.S.
- Many auto manufacturers, including General Motors and Chrysler, recommend the use of oxygenated fuels, such as ethanol, in their vehicles.
- Ethanol guards against gas line freeze by suspending moisture that may get in the fuel system during cold weather.
- Ethanol is a proven octane enhancer and replacement for MTBE, lead and other toxic compounds in gasoline.
- The blending of 10% ethanol boosts the octane rating of gasoline by an average of three points.
- Nationally, since 1978, ethanol has provided motorists with more than 2 trillion road miles of satisfactory performance.
- Ethanol-blended fuels are approved for use in small engines too -- including outboard motors, snowmobiles, lawn mowers, motorcycles, and chain saws. All small-engine manufacturers that have tested a 10% ethanol blend have approved its use.
In some states, E85 is more expensive than regular gasoline. Also, ethanol has less "oomph" than gasoline, so you'll get fewer miles per gallon than you would with a full tank of gasoline.
A History of Ethanol