API CK-4 15W-40 is a heavy-duty diesel engine oil designed for modern, high-performance engines (2017+), offering superior oxidation resistance, shear stability, and emission system protection (DPF). It is fully backward compatible with older engines (CJ-4, CI-4) and ideal for mixed fleets, demanding heavy loads, and warmer climates.
Key Uses and Applications
Modern Diesel Engines: Specifically formulated for 2017 and newer heavy-duty engines, including those with EGR and DPF (Diesel Particulate Filters), as well as Euro IV, V, and VI standards.
Heavy Duty Operations: Ideal for long-haul trucking, off-highway construction, agricultural machinery, and mining equipment, especially in severe service conditions.
Mixed Fleets: Suitable for older engines where API CJ-4, CI-4 Plus, or CI-4 is required, allowing for consolidated inventory.
High-Load Situations: Excellent for engines requiring high viscosity in hot weather or operating under high load/low speed, such as towing.
PRODUCT PERFORMANCE
API CK-4 15W-40 provides superior wear protection and soot control for modern high-output engines while remaining fully backward compatible with older standards. This advanced formula offers significantly better resistance to oil thickening and viscosity breakdown under extreme heat—up to 83% better in some cases—while ensuring enhanced shear stability for a consistent protective film. By improving oxidation and aeration control, it keeps engines cleaner, protects emission systems like DPFs, and enables longer intervals between oil changes.
