All grease is the same, right?

Wrong, says Fred Whitford, director of Purdue Pesticide Programs. He says even though about 80% of your equipment may use general purpose grease, using the wrong grease on the other 20% can lead to downtime and higher repair costs.

Recently, Whitford led an effort to pull together information on selecting the right grease. The result is PPP-145, Choosing and Applying Lubricating Grease: Using Science, Test Results, and Experience. 

Related: Greasing equipment right way helps it last longer

How do you choose the right grease? Here are three methods that lead to the same answers. All three assume your goal is using the right grease for each piece of equipment.

1. Follow specific brand recommendations in the owner’s manual. This is the place to start, Whitford says. Equipment makers use calculations and engineering principles to determine the best grease and additive combination. Then, they test and evaluate the recommended grease in the field before you ever see the equipment.

As noted, 80% of the farm tools in your shed likely operate on general purpose grease. When equipment operates in colder, hotter, wetter or drier conditions, or at higher or lower speeds than the equipment tested by the manufacturer, then grease meeting special qualifications may be needed.

Pick grease based on its characteristics, not the brand, Whitford suggests. Know that the manufacturer can’t void the warranty by law if you use a different brand than recommended in the manual. The only caveat is that the grease you choose must have the same characteristics as the recommended brand.

2. Work with a grease distributor to consolidate inventory. Suppose you have 10 pieces of equipment, and the owner’s manual for each recommends a different brand of grease. That could create an inventory nightmare. Consider visiting with a local or regional grease distributor. Take copies of grease requirements found in each owner’s manual along. Perhaps the distributor can help consolidate how many different brands you need to stock.

Deciding to use the brand your local supply store carries instead of paying attention to owner’s manuals and consulting a professional could be a costly mistake. Whitford notes that in comparison tests, a machine not greased at all often lasts longer than the same machine lubricated with the wrong grease.

3. Decide for yourself using product data sheets. The publication describes 11 tests conducted on greases before they’re classified and sold. Here’s a new word: tribology. It’s the study of friction, wear and lubrication. Speed, load and viscosity make up the backbone of this science. With enough speed and the right viscosity, you can carry enough load. These 11 tests provide measurements to predict how a specific grease formulation will perform.

Manufacturer’s display test results in a data sheet for each grease. If you want to do a deep dive into this terminology and learn how to interpret data sheets, you can select your own grease based on characteristics, then check your decision with the manufacturer. PPP-145 includes a sample data sheet.