Ethanol: Fact and Fiction

What is Ethanol, Mixing Ratios and Where is it Used?

As you may recall from science class, Ethanol is ethyl alcohol – the same type of alcohol that is used in alcoholic beverages! The Ethanol that we will discuss today is used a biofuel additive for petrol motors. Ethanol is well renown in the racing fraternity, not due to the fact that it offers 34% less energy-per-unit volume than petrol; but rather for its slower burning nature and higher octane rating – meaning that the compression ratio can be raised, allowing the vehicle to produce more power!  

Ethanol, when mixed with petrol, is named according to the percentage of ethanol by volume. E10, E15 and E85 (otherwise known as Flex-Fuel) are the three main Ethanol-Petroleum blends. E10, according to the naming convention, will have up to 10% Ethanol content, E15 being up to 15% and so on. All petrol vehicles can run an E10 blend. The U.S. Environmental Protection Agency (EPA) has approved the use of E15 for all light-duty vehicles manufactured in 2001 and above.

Flex-Fuel Vehicles (FFV’s) can run on any Ethanol-Petroleum blend up to E85 (ie. any blend up to 85% Ethanol content). These vehicles are almost identical to standard petrol vehicles; however, there are a usually a few tweaks done to the fueling system and engine. These modifications prevent the vehicle from suffering from the innate disadvantages of Ethanol – water absorption (leading to fuel-water contamination and therefore fuel separation) as well as corrosion issues as the metal tends to rust and plastic parts tend to crack over time.

What Effect Does It Have On Motor Oil?

In a journal entry by Robert Ian Taylor, from the School of Engineering at the University of Central Lancashire, Preston, he set out to observe the effects of Ethanol and other bio-fuels on the engine oil and its effectiveness thereafter. It was concluded that Ethanol significantly reduced the thickness of the ZDDP anti-wear tribo-film that gathers in highly stressed lubricated contacts. Measurements also showed that Ethanol reduced film thickness in all lubrication regimes. Due to the clean-burning nature of Ethanol and other bio-fuels, water is often produced more than when petroleum is burned – this leads to gelification. This is when the engine oil develops into a jelly-type substance and prevents the oil from flowing efficiently – sometimes resulting in engine failure. Gelification was observed mostly in oils blended using Group I & II Base Oils.

In order to prevent potentially catastrophic failures from occurring, it is advisable to change oil regularly and ensure that the correct oil specification is used.

The Myths Surrounding Ethanol Friendly Oils?

One of the greatest myths spread in the car community is that 10W-40 is the ONLY oil that you can use if you are running Ethanol in racing applications. This is simply not the case and I would love to clarify why: it is not the viscosity that shows Ethanol compatibility but rather the API specification.

For those that do not know what an API specification is:

“For more than 90 years, API (American Petroleum Institute) has led the development of petroleum, natural gas and petrochemical equipment and operating standards. These represent the industry’s collective wisdom on everything from drill bits to environmental protection and embrace proven, sound engineering and operating practices and safe, interchangeable equipment and materials. API maintains more than 700 standards and recommended practices. Many have been incorporated into state and federal regulations and they are also the most widely cited standards by the international regulatory community.”

API SN and standards released after that (such as API SP) are designed specifically to protect engines operating on Ethanol-containing fuels up to E85.

Some 10W-40’s have the specification of API SN and, we believe that the person purchasing the oil originally was under the impression that it was the viscosity that influenced the compatibility with Ethanol-containing fuels, not the specification (perpetuating this damaging local myth). This specification is not limited to 10W-40 viscosity; however, but rather to a host of other viscosity grades such as 5W-30’s and 5W-40’s.

Ravenol has over 20 oils with API SN specification. Contact our sales team so that we may assist you in choosing the right oil for your Ethanol-Burning Beast!


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