Castrol HLX is a Super High-Performance Diesel (SHPD) lubricant, specially formulated to meet the latest performance requirements of marine monograde lubricant specifications. This allows extended drain periods to effectively compete with performance normally associated with synthetic oils. HLX is available in both SAE 30 and 40 viscosity grades. HLX uses premium additive technology blended in high quality, high viscosity index base oils. It provides high detergency and excellent thermal and oxidative stability required to lubricate today's most severe diesel engine applications.