With advanced engine technologies have come advanced additives, oils and filters. I’ve also heard a lot of discussion lately about extended drain intervals and the potential savings that can come from reduced downtime and maintenance cost. And, while I am all for reducing costs whenever possible, I think it’s important to weigh the opportunity to reduce costs against the risk of reduced engine life and the cost of failures if the oil drain intervals are extended too far. It helps if you can shift your thinking away from “extending change intervals” to “optimizing change intervals.” Doing that requires a plan and a few months of consistent practice.
What follows are some suggestions to help you build your own Oil Change Optimization Plan (the consistent practice is all up to you).
1) Construct a fleet/equipment profile.
It’s important to document the equipment model, age, engine type, operating conditions, hours of operations, application severity and maintenance practices. This may seem overly basic but it is important to be able to see variance across your fleet. For example, the same engine may have a different oil volume in different equipment. Fuel and oil consumption rates can vary for different application severities and operating conditions. As critical as lubrication is to the life of your equipment, you don’t want to assume what works for one machine will work for another machine just because they are the same type of equipment.
2) Create a cost analysis that compares the costs of manufacturer’s recommended oil drain intervals with the potential cost savings associated with the optimum oil drain intervals.
The purpose of this exercise is two-fold: first, to help you establish a possible target for optimization, and second, to help validate that you have an accurate cost assessment. Costs of an oil change should include:
- Lost production
- Materials & purchasing
- Paperwork & documentation
- Labor & supervision
- Storage & handling costs (transportation, disposal, oil sampling analysis)
3) Assess the risk associated with the optimum oil drain intervals.
To get a true comparison, you will also need to estimate the cost of the risks you
could be taking by optimizing change intervals. Risk assessment should include:
- Decreased engine life
- Increased downtime for repairs
- Increased repair costs
- Decreased availability & production
Reviewing the risks is also a good for sparking ideas about what you can do to minimize them. For example, utilizing high quality, higher efficiency filters can significantly reduce contamination levels in the oil, which helps to increase engine component life.
4) Develop a testing plan for a small segment of your equipment to determine if the estimated oil drain intervals are acceptable.
To do this, you need to identify the equipment you want to include in an optimized interval test.
Everything that could have an impact on oil condition will need to be held constant during your evaluation period so you can identify the effects of application and load on oil. Here is a list of the critical factors:
- Application (relatively same load, or amount of fuel consumed per hour)
- Engine Selection (choose a group with similar, relatively low operating hours)
- Oil & Oil Filters (use the same for all engines, all changed at the same interval)
- Air Filters (change only as required by air restriction indicators)
- Cooling System Maintenance. Prior to testing, submit coolant samples for Coolant Analysis to ensure systems are optimal at test start. During testing assure that radiators are clean internally and externally. During test, maintain proper coolant and conditioner levels with Coolant Analysis at every oil change.
- Monitor operating practices (keep idle time, throttle levels consistent)
- Keep engines tuned to specifications.
- Use oil sampling analysis to validate wear and oil condition. There are four types of oil samples you need to evaluate at each change interval:
- New oil samples (reference for used oil)
- Baseline samples (identifies carryover and/or external contaminants)
- Shortened interval samples (identify oil degradation trends)
- Used Oil samples (taken at each change)
5) Begin at the recommended interval using Oil Analysis for validation and then optimize.
If wear rates and fluid conditions are acceptable throughout the testing period, I suggest you increase the change period conservatively by 50 hour increments over the recommended interval. With each increase, stay with that interval for several changes and then increase again if fluid analysis results are good.
Regular fluid analysis can also have predictive insights about what’s going on in your engine. It is similar to when going to the doctor for a check-up, the doctor will always draw blood to better understand what is going on in your body. Hence when it comes to oil, for example you should always keep a close eye on sodium levels because a rise in sodium often indicates early stage coolant leaks. You get the benefit of fixing the problem long before it shows up as coolant in the sample. Another added benefit of fluid analysis histories is that they add value at resale – giving buyers more confidence in the remaining wear life on a piece of equipment.
You also have options in terms of the types of filters and fluids available. I would begin with what’s recommended for your current application and oil change interval. If those filters and fluids are not giving you the performance you’re looking for, then explore high efficiency filters and premium fluids to see if they meet your performance and cost/value goals.
Optimizing oil change intervals takes time and analysis. If you have the experts in your organization to create an optimization team, use them. If you do not have those resources readily available, reach out to your Cat dealer team. They can help you manage testing, compare reports and make sure you get the results you want.
Caterpillar has some great information to help you. Check out these resources: