STP Gas Treatment improves the quality of gas by adding powerful cleaning agents that help fight the accumulation of harmful carbon, gum and varnish deposits in the fuel system that can reduce performance. Also engineered to remove water, which can lead to fuel line freeze. This product is made with jet fuel, a high-quality carrier of active ingredients. 5.25 fl. oz. bottle treats up to 21 gallons of gasoline. STP Gas Treatment is safe for any gasoline engines.