Directions for use: Use entire bottle of ProTecta High Mileage in engine crankcase where you add your motor oil. Good for all vehicles that require 4-5 quarts of motor oil. Refer to vehicle owner's manual if uncertain of motor oil quantity required. On larger pick up trucks etc. that require more than five (5) quarts of motor oil we recommend using two bottles. Call for technical assistance. Use at least every 6000 miles for maximum results.