Caterpillar does not recommend the use of aftermarket additives in oil. It is not necessaryto use aftermarket additives in order to achieve the machine's maximum service life or rated performance. Fully formulated, finished oils consist of base oils and of commercial additive packages. These additive packages are blended into the base oils at precise percentages in order to provide finished oils with performance characteristics that meet industry standards.

There are no industry standard tests that evaluate the performance of aftermarket additives in oil. There are also no industry standard tests that evaluate the compatibility of these aftermarket additives in a finished oil. Aftermarket additives may not be compatible with the finished oil's additive package, which could lower the performance of the finished oil. The aftermarket additive could fail to mix with the finished oil. This could produce sludge. Caterpillar discourages the use of aftermarket additives in finished oils.

More on After-Market Oil additives

General Motors Fuels and Lubricant Department Manager of Engine Oils and Chairman of the International Lubricant Standardization and Approval Committee (ILSAC) Dr. Michael L. McMillan responded in the Jan 1998 Hart's Lubricants World to claims made by aftermarket manufacturers in an Oct 1997 Hart's Lubricant World Article about the products.

McMillan said, "These supplemental aftermarket additives may upset the careful balance of additves already in engine oils, and actually cause engine harm, increase wear or adversely affect emissions or fuel economy. This is why General Motors specifically warns against the use of supplemental additives in owners manual recommendations to GM customers."

McMillan takes issue with the claim that, "the major automakers realize that such aftermarket products can significantly decrease wear and tear on engines." He states, "As a chemical engineer involved in lubricant recommendations for General Motors, I strongly disagree with this statement. Later [in the article], it is stated that engine wear can be reduced by up to 30 percent by using a motor oil ' that is correctly treated.' Where is the support for this assertion?

In response to such claims, I can only say 'Show me the data!' If these additives do all - or even any - of the things they claim to do, such as reduce engine wear, prevent metal to metal contact, improve fuel economy and reduce friction, just to name a few, it should be relatively easy to demonstrate, with data obtained in industry recognized engine performance tests, the advantages of using such additives. I know I have asked suppliers of aftermarket additives who have contacted me for just that data, but in my 25 years with General Motors, I have yet to be provided with any such documentation."

E.P.A. ruling

According to the Independent Liquid Terminals Association, a U.S. appeals court upheld a ruling saying the Environmental Protection Agency can classify recyclable oil containing chlorinated or halogenated materials as RCA hazardous waste. The American Chemical Council, which contested the classification, claims the decision subjects millions of gallons of residual oil from petrochemical facilities to the cradle-to-grave controls of the Resource Conservation and Recovery Act. The Council argued that such oil is not waste because it is recycled back to refiners, and they will likely appeal the decision. It is interesting to note that many after market oil additives, including E.R, Power-Up, Motor-Up, Prolong, and Duralube, also contain chlorinated material.