API CK-4 diesel engine oil is a high-performance heavy-duty lubricant specially developed for modern diesel engines operating under severe conditions. It is formulated with advanced additive technology to provide excellent protection against oxidation, wear, corrosion, and soot buildup.

This oil maintains optimal viscosity over long service intervals and ensures excellent piston cleanliness, even in engines equipped with emission-control systems such as EGR, DPF and SCR. It is compatible with ultra-low sulfur diesel (ULSD) fuels and is backward-compatible with previous API diesel categories (CJ-4, CI-4 Plus, CI-4, CH-4).

In short, CK-4 oils deliver longer oil life, better engine protection, and reliable performance for both on-highway and off-road diesel engines.