With the ever increasing range of synthetic oil, how do you know what synthetic oil is the best? Or even whether you should use regular or synthetic oil, for your application.

How to choose the right synthetic oil

The first step in choosing the right synthetic oil for the application is to be certain you’re comparing apples with apples - or more accurately don’t confuse “synthetic oil” with fully synthetic oil! As we’ve already seen in earlier posts, not all synthetic lubes are 100% synthetic.
Here’s a summary of the groups again:

• Groups I and II are universally referred to as mineral oils.
• Group III is the tricky collection. In the USA these are referred to as synthetic though they might be extremely refined or blended mineral oils.
• Group IV is the totally synthetic grouping.
• Group V base oils are so diverse that there is no extra catch-all description.

Advantages of a synthetic oil over regular lubricant:

• Lower friction properties
• Extended oil change intervals
• Enhanced temperature range
• Enhanced oxidation properties

Two of the key constituents of a complete lubricant are the base oil and the additive package. While the base stock is crucial for compatibility with the application, it is often the additive package that will determine which synthetic oil is best in an application test.

General requirements of synthetic oil

All oils are not created equal. Gear lube is not hydraulic fluid; compressor lubes are not motor oils and so forth. Gear oils will have anti-wear or extreme pressure additives in them. Compressor oils might have utterly different additive packages with unique corrosion and oxidation inhibitors. Synthetic motor oil used in a car or motorcycle engine, will have detergents exclusive to that required by the car, together with other additives, not present in most other types of lubricant.

The degree of additive package is clearly marked on motor oil you use in your car: The print next to “API”; such as SM, refers to the additive quality level of the motor oil. In the example of SM, it’s the highest available norm for a motor car. CF is a diesel engine or commercial vehicle norm and the highest available one is CJ-4. These are rearwards inter-changeable.

For industrial lubricants the additive packages can vary across suppliers and therefore any special requirements ought to be discussed with the manufacturer prior to making any changes.

How to confirm you’ve chosen the right synthetic oil

Once you’ve determined which lube is best suited to your application, you want to keep track of the performance over time, to accurately establish whether you have in fact selected the best synthetic oil for the application.

The best way of accurately tracking the performance over an extended time is to conduct “wear check” testing at pre-determined intervals. This can be in hours for industrial equipment or in km's/ miles for vehicles. In the end, these regular tests will offer you a significant way of monitoring degradation of both the lube and equipment, over the years, by way of:

• Oxidation levels
• Acid levels 
• Additive depletion
• Sludge build-up
• Silica content
• Wear particles

Using this system, the lifetime of the synthetic oil can be determined, from which you can map whether you’ve in fact selected the best. Bear in mind lubrication and wear are no longer the only factors to build your verdict on: You need to also look at operating costs:

• Labour and cost of filters incurred in changes.
• Time/ production lost as a result of these changes.
• Energy costs (reduced friction will decrease input energy requirements, thus saving fuel/ electricity costs)
• Extended equipment lifetime.
• Environmental impact due to less frequent oil changes.

To sum up: the issue of how to choose a synthetic oil, ought to actually be: how to choose the best synthetic oil for a given application.

To learn more about the advantages of synthetic oil take a look at this post describing synthetic lubricants, or contact Habot on our home page.