Castrol® EDGE® High Mileage 5W-30 is an advanced full synthetic motor oil that is specifically designed for vehicles with over 75,000 miles. It's been engineered to provide Superior Protection in 7 Critical Areas including corrosion prevention, sludge control, timing and friction wear and also contains a proprietary additive to protect the emission system. Our Phosphorus Replacement Technology reduces harmful phosphorus to protect the catalytic converter and extend maximum performance for your high mileage vehicle.