One gallon can. SeaFoam Auto Marine Motor Treatment is great for tuning up diesel engines and small engines. When added to diesel fuel tank, cleans fuel injectors, de-ices and removes moisture, cleans carbon as you drive, diesel fuel conditioner and anti-gel, lubricates upper cylinders, stabilizes fuel, adds lubricity. One pint treats 25 gallons of fuel. When used for Small Engine Applications, works and performs instantly to stabilize fuel, clean carburetor, clean carbon, remove moisture, assure fast starts, free sticky rings, restore power, lubricate upper cylinder and smooth rough idle.