E10 is an unleaded petrol blend that contains 9% to 10% bioethanol.
You can remove ethanol from E10 (or other blends) by phase separation – adding enough water and letting the mixture sit, which causes ethanol + water to settle at the bottom. There is some work involved, but it can be done.
To be clear, E10 is safe to use with compatible vehicles and equipment. Non-compatible engine owners need to be wary of ethanol as it can lead to damage.
I covered a bulk of the reasons in a previous post on running a lawnmower on E10 petrol. You can read this article here.
In a nutshell, ethanol is short for ethyl-alcohol, a biofuel made by fermenting starch and sugars.
Ethanol is splash blended into petrol as a diluting agent to increase octane and cut emissions.
In this post, I talk about the problems with ethanol in fuel and how to remove it from unleaded petrol.
Ethanol boosts the octane level, so removing it will drop the octane rating by 3 (give or take). So, we will briefly discuss how to remedy that as well.
How to remove ethanol from E10 unleaded fuel
Let’s take an in-depth look at how to use phase separation to remove ethanol from E10 fuel. It needs a bit of patience and a few items you can easily find online. Moreover, there are some hazards to bear in mind, which I mention in the following sections.
Exercise caution and wear the recommended safety gear to avoid accidents. Here’s a checklist of things you typically need before you start:
- Water
- Petrol containers (Fuel-safe with a tight seal)
- E10 Petrol
- Safety Gloves (Nitrile)
Food coloring agent (optional)
- Container for pouring liquid (affiliate?)
- Ethanator
Remove ethanol from E10 petrol: Step-by-step instructions:
- Put on the safety gear and head outdoors or to a well-ventilated area. Choose a slightly larger gasoline container (10% bigger) than the total quantity of liquid. You need extra room because the petrol will expand.
- Place the gasoline container on the floor. Don’t pour while holding it in your hand. Static electricity can cause sparks and ignite the fuel. Fill the container with one gallon of E10 petrol.
- Add water using a container with a spout to avoid spilling or splashing. The correct ratio is 240ml of water for 1 gallon (3.8 liters) of E10 petrol. Although it is optional, you can add a food coloring agent to the water before pouring it into the petrol. This makes it easy to see the water and E10 petrol as separate layers later.
- Seal the petrol container tightly after you have poured the liquids. Lift it up and shake it thoroughly for 30 seconds to mix the water and petrol.
- Add the mixture to an Ethanator (fuel and water separator/container). Let the mixture sit for 3 to 10 hours, overnight is ideal. Once the process is complete, you can see two layers – clear petrol settled on top and water + ethanol (with the food coloring if you added it) at the bottom.
- Ethanators have a valve at the bottom to drain the water + ethanol after it separates from petrol. You can do this with any fuel-safe container but in that case, you will have to pour off the petrol into another fuel-safe container, which is relatively difficult. Plus, there is the danger of spilling petrol if you are not careful.
- Clean up after you are done and wash your hands thoroughly. You have successfully removed ethanol from E10 unleaded fuel.
Ethanol is considered hazardous waste.
Your city may not allow you to pour it down the drain to dispose of it. Check local guidelines as you may need to take it to a waste disposal center.
Either way, get rid of the ethanol + water residue in a safe and responsible way.
Check out this video for more information.
Replenish Octane and Removing Ethanol:
Generally, a grade of petrol is measured against pure octane to obtain the octane index rating.
Fuel rated 100 would behave in the same manner as octane. Most people tend to equate the rating with petrol being more/less flammable. It’s more accurate to describe octane rating as a fuel’s capacity to resist detonation (knock).
Our goal is to remove ethanol from E10 petrol, but ethanol is directly linked to the octane level (RON). In fact, ethanol’s octane rating gives a significant net boost to the blend. If you remove ethanol, you will lower the fuel’s octane, and the change can be significant.
If you start with 87 octane petrol you will lower it to a point where it would not be wise to use it for small engines or cars.
The obvious choice is to remove ethanol from petrol with the highest octane you can find. Alternatively, you can use an octane booster to mitigate the depletion.
Be wary of what octane booster you use.
Many of them contain ethanol. Adding them to the petrol after removing ethanol would be a massive waste of time and money. So, double-check that the additive has no ethanol content before you use it.
Can you use fuel additives to remove ethanol from petrol?
No, fuel additives can’t remove ethanol from E10 petrol. Be wary of those who claim that it is possible.
Fuel additives mitigate the ill effects of ethanol in petrol. They have active ingredients that make up for the dip in mileage, the possibility of corrosion, and water absorption issues.
In other words, the fuel additives ease the negative effects of ethanol in the engine and fuel. They absolutely cannot remove ethanol from petrol once it is blended into it.
What are the main problems with ethanol in fuel?
Quick Answer:
- Ethanol attracts water from the atmosphere
- Ethanol is corrosive to metal components
- Ethanol, being a solvent, damages plastic, fiber, and rubber components
- Fuel with ethanol (E10) has a shorter shelf life (3 months)
- Ethanol blends are less efficient and lower mileage
E10 petrol is less powerful than petrol in two aspects – a) it is less efficient and b) it has a shorter shelf life.
- You can store E10 for 90 days before it starts turning green. Secondly, E10 petrol yields lower mileage (miles per gallon) compared to non-ethanol blends (1% to 3% reduction).
Ethanol is hygroscopic, which is a scientific term to describe its propensity to attract and absorb water (vapor) from the humidity in the air/atmosphere. This water uptake can create condensation in the carburetor and fuel system.
- A high content of water in fuel systems can lead to contaminated or separated fuel (fuel phase separation). If this happens, there can be serious damage and irreparable consequences.
Fortunately, studies have shown that phase separation in a small engine takes three months in a high-humidity environment, by which time the E10 fuel would be stale anyways.
The rate at which this happens is irrelevant if you take measures for maintenance and winterization.
Ethanol is highly corrosive. It helps rust to form wherever air meets metal once submerged in it. Ethanol is also a solvent.
Over time, it will fragment or disintegrate fiberglass, plastic, and rubber parts in the engine and fuel tanks. This is relevant for cars that are not E10 compatible.
Most cars sold after 2011 are E10 compatible.
The models have replaced rubber and plastic components with ethanol-resistant parts, fuel lines, and tubes. It’s advised to double-check via the official website or owner’s manual as there are exceptions.
Contact the dealer or manufacturer to check the compatibility of equipment and vehicles with small engines such as boat motors and lawnmowers. They generally update this information on their website.
Is E10 petrol safe for Classic Cars
Classic or vintage cars are designed to use pure petrol. Do not use ethanol blends of petrol (any grade) as it is highly corrosive to older fuel system components. For better or worse, finding pure petrol is either impossible or expensive due to the regulations in place.
You can blunt the problem by treating the fuel with a corrosion inhibitor and upper cylindrical lubricant.
The main steps include replacing components with ethanol-compatible equivalents. In addition, use fuel treatment to counteract the water and condensation caused by E10 petrol.
However, ensure that the fuel treatment is alcohol-free. Lastly, older cars need high octane petrol because they have higher compression engines.
Again, you need an ethanol-free additive to boost octane. I have discussed fuel additives and how to remove ethanol from E10 in a separate post..
In Conclusion
E10 petrol will pose problems if it sits in your tank for extended periods, but so will any other grade of petrol.
Now that you know about the problems associated with E10 fuel, you can take the appropriate measures to protect your garden equipment or car.
Every manufacturer of cars and equipment with small engines provides guidelines on how to safely use E10 petrol. Check for compatibility and follow the fuel recommendations to avoid any problems. Proper maintenance and winterization are equally important.
