Ask The Experts

“Would you recommend using aftermarket engine oil fortifiers? Have any studies or research been done on the benefits of using these types of oil additives?”

There are currently more than 50 products on the market that make claims of reduced engine wear, increased horsepower, improved fuel economy, etc. Just about any automotive or general store will have multiple brands and varieties. So what is in them that makes them so special, and are they beneficial?

The product data sheets for all of these products are nearly identical. With a few exceptions, most have an SAE 50 base oil with standard additives. One of the exceptions is polytetrafluoroethylene (PTFE), which was invented by Roy Plunkett of Kinetic Chemicals (DuPont) more than a half century ago. To this day, DuPont claims that “PTFE is not useful as an ingredient in oil additives or oils used for internal combustion engines.”

The NASA Lewis Research Center conducted a study in which oil additives containing PTFE were tested. The conclusions of this test were as follows: “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 the inlets and act as a dam, which simply blocks the oil from entering. Instead of helping, it is actually depriving parts of the lubricant.”

Aside from PTFE, many of these products contain a base oil, zinc, phosphorus and sulfur compounds. It should come as no surprise that this is exactly what the oil manufacturer has already put into the oil. The only difference is that when the oil manufacturer adds compounds, it is in very precise quantities, at specific temperatures and in a certain way to give the end lubricant very unique performance properties.

Think of the lubricant as a chemical soup with very specific characteristics. Mixing additional ingredients into the soup will have an effect on the outcome of the recipe. How often do you walk into a world-famous chef’s kitchen and toss in a handful of what you think it needs, not knowing what was in the soup in the first place?

Other important questions to ask before using an engine oil fortifier would include why are there so many Federal Trade Commission (FTC) fines and lawsuits against the aftermarket additive companies for misleading advertising, why don’t car manufacturers recommend their usage, where are all the official studies, and who is conducting them.

“If the environment is laden with dust like in coal-handling plants, and dust ingression is unavoidable, what type of grease or oil should be used for bearings and gearboxes?”

The dust in a harsh environment plays little role in the selection of a grease or oil. This role is reserved for attributes such as speed, load, temperature, size, etc. The major role the dust plays is in the selection of accessories and lubrication tasks to be performed on the equipment.

Ingression does not have to be unavoidable. In a harsh environment, one of the most cost-effective measures is to make every attempt possible to seal the equipment. The cost of excluding a gram of dirt is often stated as being one-tenth the cost of removing it later. This can be achieved by the use of several accessories. First and foremost is the headspace management. Every piece of equipment “breathes.” You want to make sure that when it does, it is breathing clean, dry air.

There are multiple ways to achieve this. The most popular method to control headspace ingression is the use of desiccating breathers. They not only stop very small particles (often 1 micron or smaller) from entering the headspace but moisture as well.

Your next focus should be on seals. Shaft seals must be properly selected and maintained. Some seals do a good job of retaining oil or grease but do a lousy job of excluding contamination. Lip seals are prime examples, particularly the ones that are only directed inward. These types of seals tend to wear after a period of time because they make rubbing contact with the shaft. Eventually, the seals no longer function well from the standpoint of both oil retention and contaminant exclusion.

On the other hand, a labyrinth seal is non-contacting, so it will not have the wear-out condition. These seals are excellent for excluding particle contamination and moisture, even if there’s a spray of water nearby.

Another major source of ingression can be service ports such as dipstick tubes. Unfortunately, the two most common methods for checking oil levels in gearbox applications include using either the supplied dipstick or a level port that must be removed for level confirmation. Both of these methods have the potential to introduce unwanted contamination to the system.

Modifications that may be considered for checking the oil level include the addition of a bull’s-eye sight glass into those areas where a level port exists or adding a stand-pipe-style level gauge to the drain or auxiliary side port of the gearbox. Simply adding a stand-pipe level gauge does not fully address the possibility of contamination, as it is possible to experience contaminant ingress through the vent hole of the level gauge. Applications that utilize an external level gauge should also have the gauge vented back to the case or breather assembly via a T-style fitting.

There is one last point of ingression that everyone seems to either forget or dismiss — new oil. In most every case where particle counting has been performed on new oil, it has been found to be disgustingly dirty. In fact, it is often many times dirtier than what you want running in your equipment. New oil must be cleaned before it is put into a machine component. Missing this one seemingly simple step can be the difference between a clean, reliable machine and a machine that becomes a bad actor.

If you have a question for one of Noria’s experts, email it to editor@noria.com.