Opti-Lube Summer+ Formula Diesel Fuel Additive: 4oz 8 Pack with Opti-Box Treats up to 80 Gallons per 4oz bottle Boosts Cetane by 5-7 points and Enhanced Lubricity for Reduced Fuel System Wear. Improved Water Separation and Storage Stability (More than doubles storage life of diesel fuel) Improved Fuel Economy, Increased Power Improved Storage Stability (More than doubles storage life of diesel fuel) Cleans Injectors, reduceses Deposits and Emissions. Prevents Rust & Corrosion