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OZ 6521 – Heavy-Duty Diesel Engine Oil Additive Package (API CD, TBN 11)
Cost-Effective Additive Package for High-TBN Diesel and Gearbox Applications

Description:
OZ 6521 is a minimum treat-rate, cost-effective additive package designed to meet API CD performance standards with a Total Base Number (TBN) of 11. It also meets U.S. military performance requirements for lubricants used in combined engine and gearbox applications.

Engineered for use with Group I mineral base oils, OZ 6521 delivers the high alkalinity necessary to protect diesel engines operating with high-sulfur fuels—particularly those exceeding the 25 ppm sulfur limit common in European fuel standards. The additive is especially suitable for heavy-duty diesel applications, offering both engine protection and gearbox lubrication within a single oil formulation.

Key Features:

  • Meets API CD and military-grade combined engine/gear oil requirements

  • Delivers high TBN (11) for effective acid neutralization in high-sulfur fuel environments

  • Designed for use with traditional Group I base stocks

  • Provides excellent wear protection, detergency, and oxidation stability

  • Suitable for combined engine and gear lubrication

  • Cost-effective solution for low and mid-tier diesel applications

Applications:

  • Heavy-duty diesel engines in commercial and industrial equipment

  • Lubrication of combined engine-gear systems

  • Ideal for older fleets operating in regions with high-sulfur diesel fuel

  • Suitable for blending monograde and multigrade diesel engine oils

Formulation Guidelines:

  • Blend with mineral base oil, pour point depressant, and optionally a viscosity modifier for multigrade oils

  • Follow standard blending procedures for additive incorporation and temperature control

Handling and Safety Considerations:

  • Avoid contact with water and wet gas during storage and handling

  • Do not expose to direct air contact when heated, as it may cause discoloration

  • To prevent ZDDP decomposition, avoid overheating—especially during mixing

  • Heating above 140°F (60°C) is permitted short-term, but long-term storage should not exceed 100°F (40°C)

  • Decomposition may release hydrogen sulfide, mercaptans, and olefins, requiring adequate ventilation

Packaging & Storage:

  • Supplied in 200-liter metal drums, IBC totes, or bulk containers

  • Store in dry, clean, and well-ventilated warehouses away from direct sunlight and moisture

  • Handle using standard lubricant additive practices

Product data sheets can be downloaded via the following link(s):

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