STP Gas Treatment (5.25 fluid ounces) 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. Use regularly when you fill up your tank. STP Gas Treatment is safe for any gasoline engine. This product is compatible with cap‑less gas systems.