SK Lubricants' line of Yubase Plus oils offers improved quality over conventional oils. They are the base stock in various lubricant finishing products, the company claims. Using Yubase as a base oil produces a 0W grade engine oil without costly raw materials such as Poly-Alpha-Olefin or ester. SK applies this base to products ranging from engine oils to long-drain automatic transmission fluids. Environmental benefits include improved mileage and extended drain intervals, reducing CO2 emissions. Sold in bulk without Group IV base oils, Yubase and Yubase Plus 0W grade products are used in the company's ZIC finished lubricant brand, a 100% synthetic oil with improved friction modifying features to maximize fuel efficiency. The performance-grade brand boosts engine protection under severe cold weather, and a high viscosity index base extends service intervals.