DEEP-CLEANS FUEL SYSTEM AND HELPS: SAVE GAS BY KEEPING FUEL INTAKE SYSTEM CLEAN. RESTORE PERFORMANCE. INHIBIT CORROSION. REMOVE DEPOSITS. The STP formulation of this product helps clean your entire fuel system in order to restore it to its optimum operating condition. It contains jet fuel, a high-quality carrier of active ingredients. Usage Directions: Use every oil change or at every 7,500 kms.