Schaeffers SynShield OTR Plus 5W40 Full Synthetic Oil is a premium advanced performance, synthetic plus, heavy-duty diesel engine oil formulated to provide maximum protection against wear, oxidation, deposit formation, soot contamination and aeration. SynShield OTR Plus 5W40 Full Synthetic provides excellent fuel economy while maintaining engine durability and longevity. Using our proprietary friction modifiers, Micron Moly and Penetro, SynShield OTR Plus 5W40 Full Synthetic creates a slippery, tenacious shield that prevents metal-to-metal contact for increased engine efficiency. SynShield OTR Plus 5W40 Full Synthetic is suitable for use in 2007 and 2010 emission complaint engines that utilize heavy exhaust gas recirculation (EGR) and exhaust after-treatment devices such as diesel particulate filters (DPFs) with or without diesel oxidation catalysts (DOCs) and selective catalytic reduction (SCR). Schaeffer's 5W40 is suitable for use API CK-4 specifications.