The history and science of ethanol

Ethanol is the most often used motor fuel at the present time and it is a primarily biofuel additive for gasoline. Ethanol petrol provides high quality and high octane for exceptional engine performance and high emissions. In 1908, due to the invention of the model T to be operated using alcohol, Henry Ford has paved its way for Ethanol to be used in cars. Now that we are fully aware what ethanol is, we need to learn and understand how and when the ethanol has been added in gasoline so we can be able to prevent the possible damage that this would cause to your vintage motorcycle.


Throughout the United States, ethanol has been mixed to gasoline in past decades then has to be oxygenated so as to produce cleaner-burning fuel that emits low emissions, resulting to a reduced pollution. Ethanol became a replacement to the very first oxygenate mixture with gas when the leaking of some harmful compound was discovered near the refilling stations. Nowadays, most of the pump gas that are virtually sold in the United States is E10, meaning it contains 10% of ethanol but the exact amount varies by region.

All gasoline vehicles can use E10 but most of the currently made vehicles are using fuel with a much higher amount of ethanol in gasoline. Most of the motor gasoline with more than 10% ethanol are often sold in the Midwest. Due to some stressful concerns raised by some well-known ethanol distiller and powerful corn grower lobby in the United States Midwest, ethanol has been considered as a “green fuel’ which presumably becomes the reason behind the less dependency of the United States from the foreign petrol.

It is unfortunate that some arguments that were raised that has neglected the reality of comparing the quantity of petrol use has been offset through the addition of ethanol into gasoline, it would take more fuel energy that could further assist the corn grower in growing, harvesting and transporting the corn that would eventually be distilled to ethanol before it can be finally mixed to the pump gasoline.

The main issue that could occur for vehicles including vintage motorcycles is that water vapour found in the air in humidity form can be easily captivated by the ethanol that would eventually be dissolved as the burning of ethanol and gasoline happened during start-up. As the tank’s fuel breathes in and then out though the gas vent which is being driven by the daily periodic alterations in temperature while the partially humid air tends to be repeatedly drawn in to the tank.

The same process also takes place under the ground of the refilling stations’ gas storage tanks. Ethanol isn’t added in a normal way so as to reduce the ethanol’s exposure to humidity as the refined gas has to reach the plant which serves as the final step for storage before it can be delivered to the retails stations.

Over time, ethanol in stored gas gradually picks up increasing quantity of water until it accumulates the highest amount that this can hold. When a previously warm ethanol or gas fuel containing maximum dissolved water has completely cooled, some of the ethanol or water mix will come out of the solution then it will form microscopic liquid water drops.

This phenomena is called phase separation, it is a chemical process that is very harmful to any of our gasoline-powered vehicles without the exception of the classic or vintage motorcycles to the newly manufactured family vehicles.

The problems with ethanol

The introduction of ethanol into gasoline-based fuels changes the combustion characteristics within the engine as it presents unique fuel storage challenges through the continuous use. Several concerns regarding the use of ethanol can be found on websites and other relevant form of media. The four major concerns with the ethanol-blended fuels are as follows:

  • Adding ethanol will change the way on which the fuel combusts in the engine, thepowerof its explosion and of course, the fuel efficiency. This is absolutely true since ethanol has a higher octane rating that changes the best possible compression ratio, fuel-air ratio and spark timing. Most vehicles have fuel-injection controls to change and monitor the injection of fuel depending on the ethanol content. Small two-stroke engine don’t have computerized controls and can’t make adjustments to the engine’s timing. Manufacturers have compensated for this fact and now, two-stroke engine can burn fuels with up to 10% ethanol content.
  • Ethanol puts your vehicle at high risk if the fuel tank has absorbed water. Though if fresh fuel is used or additives are mixed into the fuel, this problem can be avoided.
  • Ethanol is a solvent and it releases deposits into the fuel and combustion systems in the engine that may cause damage.
  • Ethanol dissolves, hose materials, gaskets and plastics. This is so true in classic or vintage vehicles but to most engines available for sale today, the materials are made to be alcohol resistant and won’t pose any issues in the long run.

What are the things you need to consider to prevent ethanol damage?

  • Overall, the mixture of ethanol in gasoline can put your classic vehicles at a high risk especially if you won’t be using it more often
  • Gas that contains ethanol which is stuck for more than 6 months must be discarded.
  • You may want to transfer the gasoline with ethanol to one more vehicle that you are using regularly instead of putting it to waste.
  • Use your vintage motorcycle regularly and you “deep cycle” fuel in the tank.
  • As much as possible, try using almost all of the old fuel prior to refilling your vehicle’s tank hopefully with fresher fuel from the gas stations.
  • You may also want to refill your tank’s fuel from a refutable refilling station that has frequently deliveries of quality and fresh fuel.
  • The old gasoline that has been left on the vintage bike’s tank for more than a year must be discarded. The tank must be removed and must be properly cleaned to get rid of the unused rust, water or some unnecessary substance.
  • Carburettors and gas lines should be regularly cleaned thoroughly, especially before long term storage
  • Change the fuel as often as needed.
  • Always check the tank if there’s a water existence so as to avoid major damage on your vintage motorcycle.
  • Consider adding a fuel stabiliser to mitigate the issue of phase separation and retention of water within the fuel tank.


Brian Kortmeyer · August 25, 2016 at 9:05 pm

Hi Allan. It was nice chatting with you in Houston B.C. Canada.
To further our conversation about much hated ethanol… For winter storage of my bikes I first of all don’t use ethanol gas here. 4 x1977 KZs, 1993 ZR1100. Guzzi LeMans, BMW Gt 1200 .
But sometimes it’s unavoidable. Then drain tank & carbs in old bikes. 108 octane race gas solves the problem for long term storage. Pricey ! but it works. Just run a little before shutting down for the winter. Will last years..

    Alan · September 2, 2016 at 12:29 am

    Hi Brian

    I’m back in the UK now, and reflecting on an amazing trip in Canada. Thanks for you feedback on the article. As was discussed, ethanol in fuel is becoming more of a problem for older bikes without fuel injection.

    I thought Houston was a lovely town, and enjoyed the scenery on the way to Prince Rupert.

    Keep in touch.


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