Red Line 15w40 Diesel Motor Oil - Case of 12You physically can't find a higher quality diesel motor oil then Red Line's 15w40 Diesel Motor Oil. Derived from Red Line's Race Oil line, but formulated specifically for street use in various passenger cars and light, medium and heavy trucks, Red Line Engine Oils outperform all petroleum based oils and all other synthetics on the market today. Using only the most stable components available, Red Line oils are formulated for wear protection and