However, VI improvers can be quickly depleted, leaving the oil with the base oil viscosity index. All modern greases and oils require additives to help them match specifications required by equipment manufacturers. There are different quality levels for additives, just as there are different quality levels of base oil. The type, quantity, and quality of additives has an immense role in efficiency and performance. Some additives can be used in most oils and greases, while some are used specifically in gear oil or grease.
Some additives are reactive with other additives, grease thickeners, or certain base oils.
For this reason, after market or off the shelf additives can have harmful reactions with the lubricant they are combined with. It is recommended that any additive not used during manufacturing should be avoided. Zinc, calcium, and magnesium are examples of anti-wear. Proper use of anti-wear is critical in maintaining maximum efficiency. Heat and high pressure can cause poor quality anti-wear to degrade and form acids, which attack metal.