How to Select the Right Equipment Lubricant

To maximize lubrication effectiveness, the appropriate choice of lubricant is essential and needs to be determined by the nature of the environment in which it will be used

Paying particular attention to the lubricants used, lubrication suppliers selected and overall approach to management of the lubrication maintenance functions and practices can return many benefits. Through lubrication excellence, maintenance costs are lowered, vehicle productivity is increased, equipment reliability is improved and downtime is reduced.

To maximize lubrication effectiveness, minimize cost and reduce the risk of application-induced failure, the appropriate choice of lubricant is essential and needs to be determined by the nature of the environment in which it will be used. Different types of lubricants excel at various uses, depending on their precise combination of ingredients and formulation. Therefore, when selecting lubricants, a number of factors need to be considered.

The first and most crucial function of lubricant is its ability to minimize friction and wear, says Molly Brown, a technical product manager with Amsoil. Lubricants do this by providing a protective film that separates two rubbing or moving surfaces, which helps reduce the friction between them, improving efficiency and reducing wear, adds Martin Currie, national sales manager for Justice Brothers, a manufacturer and distributor of fuel and oil additives for automotive, industrial and agricultural applications.

In addition, Brown says a lubricant must also maintain internal cleanliness, cool through the absorption of heat, seal out contaminants, cushion mechanical shock, prevent corrosion and transfer energy (hydraulics).

Intrinsic properties

Different lubricants are formulated for specific applications, says Manny Gutiérrez, director of marketing for Lucas Oil Products, a manufacturer of petroleum additives and oils for high performance engines. Selection of the proper lubricant will save money in the long run.

“Additives play an important factor in the overall quality and performance of a lubricant,” Brown points out. “Well-formulated lubricants have a precise balance of additives to ensure proper performance for the specific lubricant function.”

The additive packages that are blended into the finished product make for increased performance capabilities, adds Spencer Mackenzie, president and CEO of Omni Lubricants, manufacturer of Green Grease, a waterproof, high-performance synthetic polymer developed for trucking, mining, manufacturing, marine and off-road applications. By way of example, he says that in a recent comparison of 14-ounce grease cartridges from nine different manufacturers, only one of the greases had any extreme pressure (EP) additives.

“EP compounding is important because it gives the grease the ability to prevent wear under heavy duty conditions and extreme pressures,” he says. “EP additives, when added to grease, help boost significantly the Timken Rating which measures the load-carrying ability of a grease.”

Other additives important for a high-performance grease include synthetic polymers, anti-rust and corrosion inhibitors and anti-wear additives, notes Mackenzie.

Another “extremely important” differentiator of lubricants is base oil selection, Gutiérrez of Lucas Oil Products says. The quality levels among lubricants vary greatly, Brown says. “Base stocks are the foundation of a lubricant and should be of high quality.”

The American Petroleum Institute developed a classification system that divides base oils into five groups, she says. Groups 1 and 2 are mineral oils. Groups 3 and 4 are classified as synthetic oils. Group 5 is a catch-all group and includes all oils not classified under groups 1 to 4. Group 4 base oils are polyalphaolefins (PAO) which are chemically-engineered synthesized base stocks that “offer excellent stability, molecular uniformity and improved performance over mineral oils.”

Application area

“The area of application for a lubricant is possibly the biggest determining factor, and the area can include temperatures reached, metals involved and the cost of repair for the particular area,” Currie says

“Make sure the proper lubricant is selected for the proper application,” Gutiérrez says. “Many times failure to do this results in misapplication of the lubricant and inefficient operation or potential failure.” He recommends referencing the owner’s manual to determine the proper specifications of fluids - ATF, SAE grade of engine oil, power steering fluid, hydraulic fluid, etc. - used in each vehicle.

“The application, duty cycle and environment during use are all important factors when choosing a lubricant,” Amsoil says. “Ambient temperatures also play a role when selecting a lubricant.”

Also look at the conditions that the lubricant is going to be used in, Gutiérrez says. By way of example, if a grease is going to be used in wet applications, the grease needs to have that has excellent water resistance.

Lubricant manufacturers say that simply using a different lubricant will not some how magically make up for under- or over-greasing, inattention to lubricant condition, poor preventive maintenance practices, etc.

Price differences

Saving money by buying “cheap” lubricants is almost always a false economy. On the other extreme, buying quality lubricants to remedy bad lubrication may also save money at the beginning but over time results in more money being wasted.

“Buying ‘cheap’ grease only leads to using more grease, more time to re-apply the grease more frequently, increased parts failures and increased downtime,” Mackenzie says. “That translates into reduced productivity and lost profits,”

“You get what you pay for,” Gutiérrez says. “If you want to extend the life of your equipment, extend your oil drain intervals, reduce maintenance costs and improve economics in the long run, it is always a good idea to use high quality lubricants. You may save money in the short term by using ‘cheap’ lubricants but will pay for it in the long run with increased maintenance costs and downtime.”

Currie advises using the cost of repair of the lubricated parts, along with the downtime and associated costs, when determining how much to spend on the lubricant. “Using both of these criteria may lead you to a realization that saving money on a cheaper lubricant or additive package could actually be costing you.

“A properly operating piece of equipment is like your personal health,” he says. “It is taken for granted until a breakdown happens. It is at a time like this that you may wish you spent the extra money for better operation and longer equipment life.”

Selection drivers

There is much debate about whether synthetic lubricants are better than conventional mineral-based lubricants. When considering which type to use, lubricant manufacturers says the question should be not whether a synthetic is any better than the equivalent mineral-based lubricant, but rather, which lubricant provides the best overall combination of performance properties, based on the assessment criteria.

“You should always look at what lubricant is going to give you the best performance,” Gutiérrez says.

“While synthetic lubricants hold up over a longer service interval, some feel they would rather use conventional lubricants and change them more often to remove the contaminants that accumulate in them,” Currie says.

There are many areas where synthetic oils excel when compared to conventional oils, Brown says. “Synthetic oil does not contain paraffin (wax) and can flow easily at cold temperatures to deliver better protection during cold starts. Synthetic oil has a uniform molecular structure to maintain viscosity during temperature extremes, as well as the ability to resist high temperature volatilization (evaporation) better than conventional motor oils. Better high temperature performance helps to reduce oil consumption and emissions. Synthetic oils also have been shown to increase fuel economy when compared to conventional lubricants.”

Mixing matters

When incompatible lubricants are mixed, there will be adverse side effects. Many of today’s premium lubricant formulations have new risk factors related to lubricant cross-contamination.

Lubricants need to be compatible not only with other lubricants, Brown says, but also with seals and components to ensure long seal life.

All engine oils today have to be compatible with both synthetic and conventional products, Gutiérrez says. “When you get into more specialized lubricants, such as automotive air conditioner compressors and high dollar stationary compressors, you have to be very aware of your product selection. In automotive air condition compressors, for example, polyalkylene glycols (PAG) have been used as air conditioner lubricants but are incompatible with mineral oils. Mixing the two together will result in a significant increase in the viscosity of the lubricant and in some cases solidification.”

An easy way to explain synthetic and conventional compatibility is to use the engine oil as an example, Currie says. “If you are using 100 percent synthetic oil in your engine and had to add a few quarts of conventional oil in a pinch, you would end up with be a semi-synthetic.”

There is no problem in brand compatibility either, he says. “While one oil brand might be better than another, by mixing the two you end up with oil that is neither as good as the quality oil you added and not as bad as the lower quality oil you added.

“For the most part, lubricant compatibility may not be a problem. But with that being said, due to today’s more sophisticated systems, you need to check the manufactures specifications,” Currie suggests.

“Compatibility in greases is important because some greases are not compatible with other greases and some are only compatible with themselves and any other type of grease should not be used,” Mackenzie says. “Therefore, it is important for the end user of the grease to first find out what type of grease they are using now and then check to see if the proposed new grease is compatible with it.”

Supplier preference

When it comes to selecting lubricant suppliers, Brown says choice should be based on lubricant performance and suggests researching available products, requesting documentation of the product’s performance claims and running field trials with different lubricants to determine the best option.

Make sure that the lubricant supplier has a good reputation in the industry and stands behind the performance of their products,” Gutiérrez says. “You also want to make sure that pricing is competitive and that they can consistently supply product without delays or interruption.”

Mackenzie adds: “It is important to find products that will save time and money and a supplier with a long history of successful application experience in the toughest applications other than automotive type applications.”

The length of time a particular lubricant manufacturer has been in business and the value of products and quality of service are other important considerations, Currie says. “Also, while it may be a dying breed, personal service is an added value and can save you considerable money over years of a relationship.”

“It also helps you to find out what others in your particular type of usage are doing. It’s a forgotten benefit that can really pay-off.”

Don’t forget to also consider the services offered by the supplier, including local distribution and support for technical and applications questions.