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Ethanol & its effects

Your Engine and the Harmful Impact of Ethanol Based Petrol


If your family car, classic car, boat, motorcycle, Quad, lawnmower, strimmer,  rotovator, chainsaw, generator, pump or any other type of equipment  has a petrol engine, you need to know about Ethanol in your fuel.

What is Ethanol?

Ethanol, also called ethyl alcohol, is a volatile, flammable, colourless liquid. Best known as the type of alcohol found in alcoholic beverages, it is also used in thermometers, as a solvent and as an alcohol fuel. In common usage, it is often referred to simply as alcohol or spirits.

Where does it come from?

Ethanol is  produced from renewable resources such as corn, grains and potatoes.

Why do oil companies add Ethanol to Petrol?

Ethanol is good for our agricultural economy and helps us reduce our dependency on foreign petroleum products. On the “green” side they are aimed at improving air quality and reducing air pollution from fuel emissions.

What proportion of the fuel is Ethanol?

Permitted ethanol content in petrol is 10%. However it is possible that some cheap supermarket fuels may already have as much as 15% ethanol blended in.

While this is good for the domestic farmer and our environment, Ethanol can cause serious problems to your engine and fuel system. Generally vehicles built after 1996 have been designed with Biofuels in mind, but earlier cars and  more basic engines with carburettors are going to need help. 

What types of problems have been encountered?

  1. Water accumulation in the fuel tank - ethanol is hydrophyllic ie it absorbs water from the air. The water condenses in the fuel tank and will pull the ethanol out of suspension with the petrol. This is bad news because it strips the octane out of the petrol, leaving you with a layer of octane-poor fuel on top and a water-ethanol layer mixture on the bottom.  If this gets sucked into the combustion chamber, you will have poor starting and very rough running with the potential for engine damage. 
  2. Deposits are likely to build up - Ethanol when mixed with water readily forms Gums in the fuel system much quicker than fuel without Ethanol. These Gums coat fuel system components including filters, carburettors, injectors, throttle plates and will then form varnish and carbon deposits in the intake, on valves, and in the combustion chamber.
  3. Lower fuel mileage, Decreased performance and acceleration. Ethanol contains less chemical energy than petrol does, and this means less mileage for the driver. 3-5% drops in mileage are expected.
  4. Corrosion of internal engine components - Water contamination may cause fuel system corrosion and severe deterioration.
  5. Contaminants in fuel system – water, degraded rubber, plastic, fibreglass and rust may get drawn in.
  6. It could encourage microbial growth in fuel. Ethanol being organic  may allow the growth of fungus.
  7. Short shelf life - as short as 90 days.
  8. Corrodes plastic and rubber - Ethanol is a strong, aggressive solvent and will cause problems with rubber hoses, o-rings, seals, and gaskets. These problems are worse during extended storage when significant deterioration could take place. Hoses may delaminate, o-rings soften and break down, and fuel system components made from certain types of plastics could either soften or become hard and brittle, eventually failing. Fuel system components made from brass, copper, and aluminium may oxidize. The dissolved plastics and resins now in the fuel could end up in blocked fuel filters or gummy deposits. 
  9. Melts Fibreglass - bikes and boats with fibreglass fuel tanks can have structural failure as the Ethanol will break down and pick-up some of the materials the tanks are made from.  Again this material, dissolved from the tank, can be carried through the fuel system and can cause damage to carburettors, fuel injectors and can actually get into the combustion chambers.

You can use an alkalite fuel - ASPEN 2 for 2 stroke machines and ASPEN 4 for 4 stroke machines.


2 Stroke4 Stroke