RETTOIL 15W40 CI-4 is a high-performance SAE 15W40 SHPD engine oil, engineered for Extended Oil Drain Intervals (EODI). It is specifically formulated for use in turbocharged diesel engines—both with and without intercoolers—as well as naturally aspirated engines, including those equipped with exhaust aftertreatment systems such as Exhaust Gas Recirculation (EGR) and Selective Catalytic Reduction (SCR).
 
Approved by the American Petroleum Institute (API), RETTOIL 15W40 CI-4 ensures stable oil pressure under high thermal stress and minimizes the formation of lacquer, varnish, and sludge. This results in enhanced lubrication efficiency, contributing to extended engine life and superior operational reliability.
 
Note: This oil is not suitable for Euro IV to Euro VI engines fitted with diesel particulate filters (DPF/FAP). For such applications, synthetic mid-SAPS engine oils are recommended.