What type of fuel should I run in my Mercury 1992 100HP 2+2 outboard, in Australia?
First off gasoline by any other name is still gasoline. 87 octane is regular gasoline by US standards. 98 octane is 5 points higher octane than US high test or premium. The higher the octane, the hotter the gas will burn. Try to find lower octane gas. You don’t need 98 or even 93 octane in your boat. If you are going to leave your boat sit for months at a time get some gasoline stableizer. You should be able to find it where they sell lawn equipment with small gas engines. Or you can buy it online if you can’t find it. In the US the top brand name is StaBil. You add it to your tank and run the engine long enough for it to make it to the carbs and then you don’t have to worry about draining your carbs.
