Sunoco Optima is an ethanol-free unleaded petrol, designed to be storage stable for extended periods.
Why Use an Ethanol-Free Fuel?
Ethanol is hygroscopic, which means it attracts water. High levels of ethanol in the fuel leads to increased moisture in the engine, which can cause rust and corrosion issues. The ethanol itself is also corrosive to aluminium, bronze and zinc typically found in carburettors. Both of these issues are compounded by long periods of non-usage.
Sunoco Optima is specially formulated to be kinder on gaskets, o-rings, and other fuel system components compared to unleaded petrol. It also contains detergent additives for engine cleanliness, as well as anti-oxidants and corrosion inhibitors to extend storage life. When stored in air-tight opaque fuel containers, Optima should remain storage stable for 3-5 years.