Bell 1 Platinum Xtreme  API CJ-4/SN Diesel Engine Oil is specifically formulated for extended drain service in the most demanding applications requiring API Service Category CJ-4/SN, as well as the latest OEM's for EPA 2010 compliant on-highway and Tier 4 nonroad diesel engines equipped with after-treatment devices such as Diesel Oxidation Catalysts, Particulate Filters and Selective Catalytic Reduction system or for previous model year diesel engines. Exceeds the highest API SN gasoline engine performance as well.