Optimize Your Fleet's Drain and Regreasing Intervals

Mark Betner, CITGO Petroleum Corporation

Today’s fleet managers are trying to get every mile possible out of their oil changes and regreasing intervals. Thanks to the advances in additive technology made in recent years, many heavy-duty engine oils and lubricants on the market do a great job of helping fleet managers extend interval times. Unfortunately, great product marketing has led many to believe that oil technology alone dictates these drain and regrease intervals, but oil is only part of the solution. There are several other factors that must be considered as well.

In recent years, the pressure to save money on labor and supplies while simultaneously increasing fleet uptime has increased. Because of these demands, many fleet managers are overextending their drain and regrease intervals, which crosses into dangerous territory. Overestimating the appropriate or optimized intervals not only causes widespread engine failure, but it quickly nullifies any cost savings or profit margins resulting from these cost-cutting measures. To avoid this, it’s crucial to move away from a mindset of “extension” to one of “optimization”.

Oil Drain Optimization

Oil drain optimization is not easy, but it’s worth investing time and effort in. Fleet managers who put forth the time and effort to determine appropriate drain intervals consistently see maintenance budget savings goals being met and greater profit potential. To accomplish this, consider the following steps:

  1. Reference the engine and/or vehicle manufacturer's guidelines for oil intervals. While this is a basic step, manufacturer guidelines are often overlooked. While you will most likely choose to exceed the drain interval set by the manufacturer, its recommendation will help you to establish a baseline for optimal vehicle performance. For vehicles under warranty, however, exceeding the manufacturer's guidelines may be problematic. In these cases, it's best to consult the manufacturer directly to make sure that exceeding the manufacturer's guidelines does not void the warranty.
  2. Know the drain interval recommended by the oil filter manufacturer. Make sure to use a product built specifically for the drainage interval at which you are currently operating. If not, consider switching to an oil filter designed for longer service intervals.
  3. Evaluate the fleet profile. It’s important to ask a number of investigating questions to best determine the stress placed on the fleet. The more severe service the fleet regularly faces, such as hot or cold operating temperatures, heavy loads, and driving patterns, the shorter the drain interval should be.

To help evaluate your fleet, start by asking yourself the following:

  • What are my expectations from the fleet?
  • What improvements do I hope to achieve by pushing the drain interval?
  • What kind of load, weather, and road conditions are the vehicles operating under?
  • What is the standard engine idle time? (Long engine idle times may accelerate the rate of oil contamination and thus shorten oil drain intervals.)
  • What is our average fuel economy? How much could you improve it?
  • Consider how long you intend to keep the vehicles in your fleet. If the goal is to keep your current vehicles for 10 years or longer, pushing the drain intervals may not be in your best interest.
  • Forecast the cost savings associated with longer oil drain intervals. Be sure to consider necessary investments in areas such as upgraded supplies, and shortened engine rebuild frequencies. Seeing the cost/savings ratio will help you determine if extending the drain interval is a worthwhile venture.
  • Communicate any maintenance changes to the drivers. Once you determine the optimal drain interval for your fleet, it's important to communicate that interval to the drivers and logistics manager. This will ensure the vehicle comes in for maintenance as scheduled.

In rare instances, after walking through the above steps, the optimal drain interval may still not be clear. In such instances, it's beneficial to call a meeting with the representatives from the engine, oil, and filter manufacturers. When meeting with this group, outline the reasons for pursuing an optimal drain interval program and the desired goals. Together, they should be able to determine if these goals are realistic, and develop a program that includes the most appropriate products for your needs and circumstances.

The Oil Analysis Link

Whenever working with drain intervals that exceed the engine manufacturer's recommendation, strongly consider implementing an oil analysis program. Though oil analysis is often rejected because of the perceived cost, it is a cornerstone of any great fleet preventive maintenance program. It provides valuable information about the condition of the equipment, the condition of the oil, and the presence of contaminants in the oil.

An oil analysis can also provide savings through the adoption of new routines and habits based on the information gathered. For example, by using an oil analysis to determine the optimum oil drain frequency, you can reduce the routine sampling frequency and the number of tests performed, saving you valuable time and money.

If these steps seem excessive, they aren't. Considering the fact that most fleets on the road today have engines less than 10 years old, overextending drain intervals not only puts you at risk of unit failure, but you may also have to deal with extensive paperwork and questions if the engine is still under warranty. The engine manufacturer may ask for the service records and oil analysis history, which is used to determine if the problem was due to a faulty engine or lack of proper maintenance.

Oil analysis can also be beneficial in improving the resale value of the power unit. For example, if you were in the market for a used truck, you would rather purchase the vehicle that comes with an oil analysis history showing excellent engine wear trends and system maintenance over one that has no history available. Above all, oil analysis acts as a report card for the fleet. It allows you to spot problems, often before they arise, ensuring maximum service life for your equipment.

Grease Lubrication

The function of grease is to remain in contact with and lubricate moving surfaces without leaking out under the force of gravity, centrifugal action, or pressure. Its major practical requirement is that it retains its properties under shear forces at all temperatures it experiences during use. For example, construction facilities that deal with extreme and fluctuating temperatures need specialized, heavy-duty greases to operate at peak performance. 

There are several functional properties of grease to be aware of and take into consideration during your grease selection. By choosing the proper grease for your equipment needs, you can effectively cut down on regreasing intervals without compromising on the quality of care that your machinery receives.

  1. Grease functions as a sealant to minimize leakage and to keep out contaminants. Because of its consistency, grease acts as a sealant to prevent lubricant leakage and the entrance of corrosive contaminants and foreign materials. It also acts to keep deteriorated seals effective.
  2. Grease is easier to contain than oil. Oil lubrication can require an expensive system of circulating equipment and complex retention devices. In comparison, grease, by virtue of its rigidity, is easily confined with simplified, less costly retention devices.
  3. Grease holds solid lubricants in suspension. Finely ground solid lubricants, such as molybdenum disulfide (moly) and graphite, are mixed with grease in high-temperature service or in extreme high-pressure applications. Grease holds solids in suspension, helping to prevent damage from occurring.

When selecting a grease to help maximize the timeframe between each regreasing, there are several important characteristics to look for.

  • Extended service capabilities with stay-in-place performance
  • Water and corrosion resistance
  • Maximum load-carrying capabilities
  • Extreme durability while still allowing for good mobility and pumpability
  • Flexibility to use in a wide variety of applications

Selecting the proper lubricating grease not only protects your fleet against contamination and its damaging effects, but also ensures you are having to regrease less, saving valuable time and money. By working with your knowledgeable staff and partnering with a quality lubrication specialist, you can select the best grease for your team and keep your fleet on the road.


Optimized drain and regreasing intervals can be achieved if you take the time to objectively evaluate your current maintenance program, set goals, draw on the expertise of suppliers, and make full use of regular maintenance and oil analysis. Most importantly, because federal regulations and your fiscal responsibilities change regularly, plan to reevaluate your preventive maintenance program every year. At that time, verify any actual cost savings or fleet uptime increases you enjoyed the previous 12 months, consider any maintenance issues you faced, and make the necessary adjustments to the program.

Though there is no magic formula for achieving the ideal fleet maintenance program, especially where drain and regreasing intervals are concerned, partnering with a trusted lubrication supplier and implementing the steps described above can help you get the most out of your budget and ensure your fleet is as productive as possible.

Subscribe to Machinery Lubrication

About the Author