Pour Sea Foam in your fuel tank to clean & lubricate your entire fuel system. Safe & effective when used in all gasoline or diesel engines ? just pour it in! For regular fuel system maintenance, add 1 ounce per gallon of fuel. For cleaning, use 2 or more ounces per gallon ? the more you add to fuel, the better it cleans! Don’t worry if you exceed these amounts: Sea Foam only contains petroleum-based cleaning and lubricating ingredients that CAN’T HARM your engine or fuel system components. For cars & trucks driven regularly, put 1 to 2 cans of Sea Foam in your fuel tank every 3,000 miles. For engine equipment used regularly, add 1 ounce of Sea Foam per gallon to a fresh tank fill every 3 months or sooner. For all other engines & fuel tanks (not used regularly): Add Sea Foam to every tank of fuel.