Well Lube Ultimate 5W40 Fully Synthetic Engine Oil is a Multi-Grade High Mileage Engine Oil that is engineered for the ultimate performance and designed to provide outstanding engine protection. It is formulated using V-NANO, ester-based nanotechnology combined with fully synthetic, hydro-treated, paraffinic base oils and technologically advanced additive system to deliver exceptional resistance to thermal viscosity breakdown, outstanding low temperature fluidity, resist engine component wear and deposit formation under severe driving conditions.