Stored fuel deteriorates in 60 days causing vanish deposits to build up in engines resulting in starting problems, poor performance and reduced engine life. STA-BIL keeps fuel fresh for 12 months. Plus it contains a water remover to prevent corrosion and a fuel injector and carburetor cleaner to restore power. STA-BIL eliminates the need to drain fuel prior to storage and ensures quick starts in all 2 & 4 cycle engines. It is safe to us in all cars, boat motors, lawnmowers, motor homes, tractors, motorcycles, snowmobiles, leaf blowers and generators. Use in gasoline, gasoline/oil mixtures and ethanol blends. Can be used for up to two years after opening bottle. 1 oz treats 2-1/2 gallons.