Should you use Ethanol blended fuels in your classic car? The short answer is ABSOLUTELY NOT.
What is Ethanol
Ethanol also known as Ethyl Alcohol (Chemical Symbol C2H50H or C2H60H) is a bio fuel distilled from corn, sugarcane, other crops and sometimes meat extracts. It is a potent solvent, and is particularly hydroscopic (Combines easily with water in the atmosphere). These two features remain constant when used as an additive in petrol and it also changes the petrol’s octane rating. Ethanol is readily contaminated by absorbing water during storage and transportation, eg at the manufacturing facilities storage, tanker transport to petrol refinery and then to fuel depot tanks and finally in your own fuel tank. Once the Ethanol absorbs a certain volume of water, it leads to “Phase Separation” where the Ethanol and water mixture separate from the petrol and settle in the bottom of your fuel tank. A cause of rusted out steel tanks.
Ethanol and your classic car
The solvent properties of Ethanol mean that it can dissolve rubber, plastic, fibreglass and some metals, including brass and aluminium. Most cars manufactured after 2000 have been designed to operate on ethanol blend fuels without ill effects. Manufacturers recommendations should be checked for cars made between 1986 and 2000 and generally that no car produced prior to 1986, or any car with carburettors, should be subjected to Ethanol blend fuels.
In our classic cars, the use of Ethanol blended fuels can mean damaged electric fuel pumps, fuel lines, filters, seals in carburettors and any rubber or plastic components elsewhere in the fuel system. This dissolved “gunk” can then progress into the engine causing damaged valves and valve seats.
Since the Octane rating of the petrol is changed by the addition of Ethanol, eg. 91 octane fuel with 10% Ethanol (E10) becomes 94 octane rating. This can cause engine knocking, which is caused by the fuel/air mixture igniting prematurely, causing overheating and damage to the engine, sometimes including catastrophic engine failure requiring major very expensive repairs.
All of the above problems are exacerbated when our classic cars are left standing for periods of time, as opposed to daily use vehicles. The Ethanol in laid up vehicle fuels can oxidise creating acidic by-products that corrode brass and aluminium components and rust steel tanks and tubing.
How to avoid these problems
Avoid the use of Ethanol blended fuels where possible. Only use fuels recommended by your vehicle manufacturer.
Replace fuel system components with ethanol compatible materials where possible. A list of Ethanol incompatible materials and their suggested replacements can be found on the fuels page of the Federation of British historic Vehicle Clubs website at www.fbhvc.co.uk/fuels
Australian Fuel Standards
A search of the Australian Fuel Quality Standards Act 2000 and the associated Regulations 2019, as amended, advise only that fuels in Australia may contain a maximum of 10% Ethanol, which must be advertised as E10 by retailers, but it appears that by ministerial approval, most Australian fuels may contain varying lesser amounts with no requirement to advertise same. Only your Fuel supplier, eg Ampol, Shell Caltex etc may know which, if any, fuels they add Ethanol to and in what percentage. Whether they will tell you or not may be a different story. The only solution to this situation would appear to be Australian Government legislation (ie by an amendment to the Regulations) requiring fuel company’s to display any Ethanol content in any fuel at retail outlets.
By Ken Burke
