STP Heavy Duty Ceramic Oil Treatment protects your engine for up to 20,000 miles. Advanced Lubrication Technology is specially formulated for large and commercial vehicles. Add this STP oil treatment to your car care routine to help protect vehicles under extreme conditions and severe temperatures. Heavy protection extends your trucks engine life and the ceramic layer prevents build-up. Add this automotive cleaner treatment at 20% of the system's capacity for best results. This auto cleaner treatment is for use in conventional or synthetic motor oils and is safe for all gas and diesel engines.