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What You Need to Know About Hot and Cold Blend Lubricants

Lubricants play a key role in your engine’s performance, as they promote movement and sliding between the two surfaces. In general, lubricants reduce friction and wear, prevent seizure, contribute to cooling, remove impurities such as dust and debris, and protect against corrosion.

In this way, they are very useful, but manufacturing lubricants isn’t an easy task. There’s a variety of factors which affect the overall quality of the product – and one of the key factors is whether the elements are hot blended or cold blended.

The Base Stock

Before blending can occur, the base stock and additives must be determined. The base stock is chosen from 5 groups – groups 1, 2, 3, 4 or 5, raising in quality as the group number increases. Once a base stock is determined, additives will be chosen which will affect the quality of the lubricant, as well as determine the application.

Blending the Lubricant

Blending occurs after the base stock and additives have been selected, and finding the ideal temperature will prolong the performance and life of your lubricant. It is generally agreed that the superior process is hot blending, as it results in lubricants that have all components blended correctly. This process itself reduces additive drop out, and ensures a longer shelf life for the lubricants. Synthetic oils are recommended for hot blending as they can withstand higher operating temperatures without breaking down. However, be careful not to use too much heat!  On the other hand, the temperature used in the cold blending process can stress lubricants. Lubricants that are cold blended can chemically degrade, do experience additive drop out, separate into phases and exhibit altered physical states. This results in a shorter shelf life and a lower quality of product in general. Some examples of the reactions from the cold blended process are:·        

  • Paraffinic base stocks can become waxy and form gels.
  • Many additives that depend on heat-induced chemical reactions fail to perform (certain EP and AW additives, for instance).
  • Oil can become too viscous to circulate and grease too stiff to feed.
  • Contaminants by-pass filters as thickened cold oil opens relief valves.
  • Engines won't crank and moving parts in other machines may become locked up.
  • Oil rings, slingers, paddle gears and other oil-lifting devices will often fail to work.

Choosing the right lubricant is important, as you want to ensure your product will last and perform at the optimal level. For more information on hot and cold blend lubricants, contact the friendly team at QP Lubes today.