Oil additive

Oil additives are chemical compounds that improve the lubricant performance of base oil (or oil "base stock"). The manufacturer of many different oils can utilize the same base stock for each formulation and can choose different additives for each specific application. Additives comprise up to 5% by weight of some oils.[1]

Nearly all commercial motor oils contain additives, whether the oils are synthetic or petroleum based. Essentially, only the American Petroleum Institute (API) Service SA motor oils have no additives, and they are therefore incapable of protecting modern engines.[2] The choice of additives is determined by the application, e.g. the oil for a diesel engine with direct injection in a pickup truck (API Service CJ-4) has different additives than the oil used in a small gasoline-powered outboard motor on a boat (2-cycle engine oil).

Types of additives

Oil additives are vital for the proper lubrication and prolonged use of motor oil in modern internal combustion engines. Without many of these, the oil would become contaminated, break down, leak out, or not properly protect engine parts at all operating temperatures. Just as important are additives for oils used inside gearboxes, automatic transmissions, and bearings. Some of the most important additives include those used for viscosity and lubricity, contaminant control, for the control of chemical breakdown, and for seal conditioning. Some additives permit lubricants to perform better under severe conditions, such as extreme pressures and temperatures and high levels of contamination.

Controlling chemical breakdown

Chemical structure of a zinc dialkyldithiophosphate, a typical antiwear agent found in many motor oils.

viscosity index improver

For lubricity

For contaminant control

Rust inhibitors

Additives in the aftermarket and controversy

Although motor oil is manufactured with numerous additives, aftermarket oil additives exist, too. A glaring inconsistency of mass-marketed aftermarket oil additives is that they often use additives which are foreign to motor oil. On the other hand, commercial additives are also sold that are designed for extended drain intervals (to replace depleted additives in used oil) or for formulating oils in situ (to make a custom motor oil from base stock). Commercial additives are identical to the additives found in off-the-shelf motor oil, while mass-marketed additives have some of each.

Some mass-market oil additives have caused a major backlash by consumers and the U.S. Federal Trade Commission which investigated many mass-marketed engine oil additives in the late 1990s.

Although PTFE, a solid, was used in some aftermarket oil additives, users alleged that the PTFE clumped together, clogging filters. Certain people in the 1990s have reported that this was corroborated by NASA[7] and U.S. universities.[8] One thing to note, in defense of PTFE, is that if the particles are smaller than what was apparently used in the 1980s and 1990s, then PTFE can be an effective lubricant in suspension.[9] The size of the particle and many other interrelated components of a lubricant make it difficult to make blanket statements about whether PTFE is useful or harmful. Although PTFE has been called "the slickest substance known to man",[10][11] it would hardly do any good if it remains in the oil filter.

See also

External links

References

  1. 1 2 Thorsten Bartels et al. "Lubricants and Lubrication" in Ullmann's Encyclopedia of Industrial Chemistry, 2005, Weinheim. doi:10.1002/14356007.a15_423
  2. API's Engine Oil Guide, 2006
  3. Chevron Oronite's Diesel Additives
  4. Roger F. Sebenik et al. "Molybdenum and Molybdenum Compounds" in Ullmann's Encyclopedia of Chemical Technology 2005; Wiley-VCH, Weinheim. doi:10.1002/14356007.a16_655
  5. Whale oil dexron Turbo hydra-matic 350 By Ron Sessions], page 20.
  6. http://www.mustangmonthly.com/techarticles/mump_0907_zddp_zinc_additive_engine_oil/index.html
  7. A NASA research report is purported to say about PTFE oil additives, "In the types of bearing surface contact we have looked at, we have seen no benefit. In some cases we have seen detrimental effect. The solids in the oil tend to accumulate at inlets and act as a dam, which simply blocks the oil from entering. Instead of helping, it is actually depriving parts of lubricant." The source of this quote is unknown, but the quote itself appears in the magazine article referenced below.
  8. See Road Rider Magazine (now Motorcycle Consumer News) article from August 1992 by Fred Rau, which has been reprinted extensively, and see oilsfilters.htm for a contemporary discussion.
  9. See Nanoflon, a PTFE that is small enough for suspension in lubricants and used commercially for that purpose.
  10. Presenting PTFE: A Potent Resin, A Well-Kept Secret by Owen Heatwole, April 1981, for QMI.
  11. QMI Products ad
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