Does ethanol hurt older engines?
The ethanol in the fuel is still doing damage. Many older fuel system components weren't designed to resist alcohol's corrosive properties, and as ethanol travels through the system it can cause considerable damage.
Unfortunately, running vintage cars on contemporary gasoline containing ethanol can create problems for classic car owners. Most of these cars run best on pure gasoline, not gasoline treated with ethanol.
Pure ethanol – 100% ethanol or E100 – could theoretically be used to power cars, but generally isn't, for numerous reasons: Ethanol is bad for cold-starting, because it doesn't burn as quickly as gasoline. (It has a higher octane, if you're interested.) Pure ethanol would be useless as fuel in the winter months.
Today's spark-ignited, carbureted engines used in pumps, generators, power washers and other equipment utilized by pumpers every day are designed to run on E0 (100 percent gasoline) to E10 (10 percent ethanol, 90 percent gasoline) fuels.
If moist air gets into the tank, the ethanol will absorb the water and can lead to running problems and rust. Ethanol can also corrode fiberglass and rubber, often found in classic cars. To keep your classic car in great shape, we recommend filling it with non-ethanol gas.
For many classic cars, ordinary Euro 95 is more than sufficient. It is important however, to ensure that not too much ethanol has been added. For example, E10 gasoline (with 10% ethanol) is absolutely out of the question.
As a solvent, ethanol attacks both the metallic and rubber based fuels lines, and other fuel system components. Ethanol also has an affinity to water that can result in corrosion of fuel tanks and fuel lines. Rust resulting from this corrosion can ultimately block the fuel supply rendering the engine inoperable.
In 2012, the government approved the use of E15 gasoline in any vehicle made after 2001, though not all manufacturers were on board at the time. Today, the majority of vehicles made by GM, Chrysler, Ford, Honda, Volkswagen, Toyota, Land Rover and Jaguar are manufactured and approved for the use of E15 gasoline.
Flex-fuel vehicles (FFV) have engines that can run on flexible fuel — a combination of petrol and ethanol, which can include up to 100% ethanol.
Continually filling a standard gasoline car with this high-ethanol fuel can result in serious fuel system corrosion. Plus, when you accidentally put E85 fuel in a car, it may void your engine warranty. That means you could be on the hook for the repairs, even if your car is brand new.
What engines can take ethanol?
Flexible fuel vehicles (FFVs) have an internal combustion engine and are capable of operating on gasoline and any blend of gasoline and ethanol up to 83%. E85 (or flex fuel) is a gasoline-ethanol blend containing 51% to 83% ethanol, depending on geography and season.
Anhydrous ethanol can be blended with gasoline (petrol) for use in gasoline engines, but with high ethanol content only after minor engine modifications.
Ethanol blends can corrode your carburetor, fuel tank, and other fuel system components and damage engine seals and O-rings, according to industry experts. And that means costly repairs at the very least–and engine damage at worst.
Alcohol is also “hygroscopic” and likes water, so when water gets into fuel during a fill-up or from condensation, it can mix with the ethanol, creating a chemical combo that causes rust, corrosion, acids and sticky varnish that wreak havoc in fuel systems, especially carburetors.
Ethanol doesn't eat rubber. So the seals and rubber hoses within your fuel system will remain safe.
Older engines can be more susceptible to pre-ignition, and using premium fuel can help to prevent it.
Replace your spark plugs, oxygen sensor, and air and fuel filters, all of which contribute to a longer vehicle lifespan. Combined, these components help ensure that your car uses the optimal mixture of air and fuel for proper operation as well as help the engine burn fuel more efficiently.
| Year | Average Compression Ratio for New Light Vehicles | Average Octane Rating (AKI) |
|---|---|---|
| 1967 | 9.26 | 89.77 |
| 1968 | 9.43 | 89.84 |
| 1969 | 9.48 | 90.02 |
| 1970 | 9.52 | 90.05 |
If you put E10 fuel in an incompatible car it will still run, but seals, plastics and metals may be damaged over longer periods as a result of bioethanol's corrosive properties.
Anyone owning a car made before 2002 is advised not to use E10 – and it can even affect cars made up until 2011. That's a good number of so-called modern classic cars, in addition to classic models.
Is there an additive for E10 fuel for older cars?
For cars older than 1996, they recommend Castrol's Classic Valvemaster which can help to prevent corrosion. This mix also contains an ethanol stabiliser which can limit the effects of the new E10 fuel. Hagerty has recommended Millers Ethanol Protection Additive or Lucas Oil Ethanol Fuel Conditioner.
There are alcohol-driven engines, and you could use a vodka-fired Stirling engine easily enough, but you can't dump liquor into your gas tank without killing your car. (Though if it's rated for E85, you might be able to pull it off. ) Alcohol is not a very good fuel, lacking a high energy density.
There are actually already whiskey-fueled cars in Scotland. Using the whiskey byproduct reduces the trucks' carbon emissions by 90%. The scientist who made the discovery says whiskey waste can be used for more than just biofuels.
For many people, beer has been used as fuel for drunken adventures--or misadventures, as the case may be. However, scientists have found that this type of alcoholic beverage can be used for another type of fuel altogether—as an alternative to diesel or gasoline.
To check if your car is a flex fuel vehicle, the U.S. Department of Energy suggests looking for a few signs: Yellow-colored gas cap or a flex fuel label near where you pump gas. Markers on the outside of the car with the labels: E85, FFV or Flex Fuel. Reference to E85 in the owner's manual.
If your vehicle is fuel injected, and is 1995 or newer, you will only need two things in order to convert your engine to flex fuel. You will need an electronic control module that plugs in between the fuel injectors and the factory fuel injector electrical connectors.
For one thing, ethanol contains only about two thirds of the chemical energy in an equivalent amount of gasoline. Aside from reducing overall fuel economy (negating some of ethanol's environmental benefit), the lower energy density can cause certain motors to run too lean.
Can cars really run on moonshine? Only if it's really strong stuff. To power a car, moonshine—in this case, illicit homemade whiskey—must have an extremely high alcohol content, at minimum 150 proof (or 75 percent alcohol by volume), or 190 proof for best results.
Fuel Economy and Performance
The impact to fuel economy varies depending on the energy difference in the blend used. For example, E85 that contains 83% ethanol content has about 27% less energy per gallon than gasoline (the impact to fuel economy lessens as ethanol content decreases).
Adjusting for this yields the figure below, which shows that ethanol in gasoline equivalent gallons is rarely cheaper than gasoline, typically 5% of the time.
Does ethanol increase horsepower?
High-octane fuels, like ethanol, help deliver more horsepower and speed. Most cars require fuel with a minimum octane rating of 87. Ethanol's octane rating is 113 and is added to petroleum-based fuels to create a blend with at least 87 octane for use in modern vehicles.
Most cars today can run on ethanol gas blends up to E15 (15% ethanol) and on non-ethanol gasoline. And flex fuel vehicles can handle up to E85 (85% ethanol) without a problem.
It is perfectly safe to used ethanol-blended fuel (E10) in your lawn mower and other equipment powered by a small engine. This post was updated in March 2022.
Almost any gasoline-powered engine can be made to run well on alcohol. Only minor and inexpensive modifications to the engine are required. Anyone with reasonable, mechanical skill and common handtools can make the modifications once they've learned the procedure.
Two stroke air cooled engines are approved to use a 87 octane rated clean gasoline in emergency situations. Alternative fuels, such as E-15 (15% ethanol), E-20 (20% ethanol), E-85 (85% ethanol) are NOT classified as gasoline and are NOT approved for use in outdoor power equipment engines.
Ethanol can damage many parts of your car at concentrations above 10%. Ethanol can destroy gas tanks, fuel pumps, gaskets, and attract moisture into your fuel. Engines can be completely ruined over time if they're not designed for ethanol.
According to the U.S. Department of Energy, vehicles typically go 3 to 4 percent fewer miles per gallon on E10 and 4 to 5 percent fewer miles per gallon on E15, because ethanol packs only about two-thirds the BTU's of gasoline.
The EPA and an academic study have said that fuel containing 15% ethanol is safe for cars, trucks and sport-utility vehicles made in 2001 or later — which make up more than 90% of the vehicles on U.S. roads.