Opti-Lube XPD Formula Diesel Fuel Additive: Quart Treats up to 128 Gallons Enhanced Lubricity for Reduced Fuel System Wear Improved Fuel Economy, Increased Power Cleans Injectors and keeps them clean! Reduced Deposits and Emissions. Prevents Rust & Corrosion Improved Water Separation, Cold Weather Performance and Storage Stability (More than doubles storage life of diesel fuel) Compatible with all vehicle emissions systems