When you visit the doctor's office for a checkup, one of the first things the nurse does is draw blood from your arm, because blood tests are an easy and fast way to isolate problems such as high cholesterol or increased insulin levels. In effect, blood tests allow the doctor to look inside your body without actually cutting you open. That same philosophy is at work when it comes to oil analysis for trucks.
Taking regular samples of truck engine oil — and of other on-board liquids, such as engine coolant and hydraulic fluid — for testing allows fleet personnel to look inside vehicles to pinpoint a potential problem before a truck breaks down, thus reducing a truck's downtime. Regular sampling also helps a refuse fleet see if the engine oil is wearing out under a vehicle's day-to-day strain or if the drain interval can be extended — which saves the fleet money on oil purchasing costs.
“Let's face it, refuse trucks operate in a very dirty environment, and the severe nature of the operation can generate fuel or soot contamination in the engine oil,” says Ed Kellerman, manager of Oil Analyzers, the oil testing division of Superior, Wis.-based lubricant manufacturer Amsoil. “Without oil analysis, you would not be able to know if you are having any contamination issues, or if the wear trends are indicating the need to schedule the truck for servicing. That's why it's a critical preventative maintenance tool.”
Tejuana Edmond, heavy-duty/OEM trade marketing manager for Wayne, N.J.-based BP Lubricants, echoes those sentiments. “By using oil analysis this way, a fleet manager always knows what's going on inside the engine,” she says. “Our oil analysis program tests for 21 different metals and chemicals that may indicate a problem — and that information becomes part of a historical database that fleets can use to take better care of their vehicles during their ownership period.”
Oil analysis programs typically are used to keep an eye out for a wide variety of trends that can adversely affect engine life and lead to unexpected breakdowns and costly repairs. For example, oil analysis can detect an increase in silicon from the air filter, which indicates the need for air inlet and filter inspections, Kellerman says. Oil analysis also can help determine if a different filter should be used to help prolong the life of the engine and the oil.
Regular analysis of the engine oil can indicate if it is overly contaminated with soot — a by-product of exhaust gas recirculation (EGR), a system used by many manufacturers to “burn off” particulate emissions by recirculating exhaust back through the engine's combustion chamber. Excessive soot loading can reduce the life expectancy of the oil. “Without oil analysis, you would not be able to know if you are having any contamination issues, or if the wear trends are indicating the need to schedule the truck for servicing,” Kellerman says.
Refuse fleets, in particular, put a lot of stress on engine oil, says Walt Silveria, U.S. technical manger for Houston-based Shell Lubricants. “There's no doubt about it: any kind of stop-and-go environment coupled to the high engine idle time necessary to run the trash compactors and lift arms on today's refuse vehicles are tough on engine oil,” he says. “Add hot and cold temperatures to the heavy loads on the engines, and you can easily see why having an internal ‘snapshot’ of how the oil is holding up can be important to a fleet manager.”
Typically, most diesel engine manufacturers recommend that refuse trucks using conventional diesel oil change the oil every 300 hours, using hours instead of miles as a marker because these trucks do not accumulate high mileages and run at low engine RPM. One of the waste fleets that Kellerman works with has extended its engine oil drain interval beyond 300 hours based on the specific data gathered from regular analysis of its vehicles' engine oil.
Some factors influencing the frequency of oil changes and whether they can be delayed include the climate the truck is used in and the driver, says Darryn Wallace, a senior technical service specialist with Amsoil. “In the summer time, the oil may be extended longer than in the winter, or vice versa, depending on where the fleet is located,” he says. “The driver can also be a factor in extending oil drain intervals, as more aggressive driving can put more strain on the oil versus a driver who is easier on their equipment.”
Not only does oil analysis provide an “early warning” system to detect problems before they shut the truck down and to help adjust oil drain intervals, it also helps fleets determine if they are using the right type of engine oil. “It helps you understand the parameters of the lubricant you are currently using, so you can make a more informed choice,” Silveria says. “It also helps you compare engine models and gauge the impact of specific applications and driving habits on the oil as well as the vehicle as a whole.”
Cranking It Up
The beginning is the toughest part of an oil analysis program, says Shawn Ewing, technical coordinator-heavy duty lubricants for Houston-based ConocoPhillips. During this time, a fleet has to pull together a lot of specific information about the trucks that will be monitored during the program, such as chassis and engine brand, horsepower and torque ratings, model number, type of route, and type of engine oil used.
“But once you get a truck set up in the oil analysis database, that's it,” Ewing says. “All the real time-consuming work is done on the front end. Once it's in the system, then all you need to do is start taking samples, label them with the truck's model number or some other designator, and mail them into the oil analysis laboratory.”
A fleet's lubricant supplier should be able to set up an oil analysis program easily, either for free as part of the engine oil supply contract or for a small fee, says Mark Betner, heavy-duty lubricant manager for Houston-based Citgo Lubricants. “A good rule of thumb is that oil analysis is worth about $10 a sample,” he says.
A mid-sized fleet should initially choose 10 or 12 units representing a cross-section of vehicles by age and application, then take frequent oil samples — approximately two per oil drain interval, building up a six-month repository of data, says Eric Olsen, a staff engineer with San Ramon, Calif.-based Chevron's engine oils team. “That should generate enough baseline data for a fleet to start looking into extending drain intervals, changing oil type and characterizing overall vehicle health,” he says.
The sampling itself is fairly easy to perform, as most oil suppliers provide an inexpensive valve that is installed in a specific spot on the engine where a representative sample can be extracted. Oil analysis labs can usually turn samples around in 24 to 72 hours. Most labs now post the results on secure Web sites so that fleets can access them in real time. “Having the information online in an electronic format helps the fleet spot trends quickly,” Shell's Silveria says. “We're also revamping our oil analysis program so we can make the data more useful to customers — coding results by color, such as green, yellow or red — to communicate potentially important maintenance issues quickly.”
ConocoPhillips' Ewing adds that it takes a minimum of three to four oil samples to establish a baseline for each vehicle and cautions fleets not to make snap judgments based on the results of only one oil sample. Fleets should establish a sampling routine, which means taking the samples at the same time and place, and quickly sending them to the lab.
“Don't let the samples sit for a week,” he says. “Be proactive in letting the lab know of any changes you make. If you do major work to the engine or change the oil type, let the lab know that, as those changes affect what they'll see in the analysis.”
Once fleets commit to oil analysis, they should perform it regularly. “A fleet must also recognize that oil analysis must be an ongoing program - you can't sample the oil once or twice a year,” Olsen says. “To detect potential equipment failures and adjust your preventive maintenance [PM] programs accordingly, oil analysis must become a regular component of the fleet's equipment service practices.”
Fleets get several concrete benefits from oil analysis and need to keep them in mind as they set up a program, Citgo's Betner says. An oil analysis can warn fleet managers of an imminent breakdown. For instance, “if you see engine coolant in the oil, you know you have an immediate problem and need to get the truck in for service right away,” he says.
Fuel contamination, air intake dirt, excessive soot and oil filter plugging also can be detected using oil analysis, which can help improve preventive maintenance practices. In the long run, oil analysis can help fleets extended oil drain intervals or switch to an oil that allows them to achieve extended drains. “Say you get to cut your oil changes in half, from 10 to five per vehicle per year — that could save you between $600 to $900 per vehicle annually,” Betner says. “That adds up significantly over time.”
Finally, the impact on the vehicle's residual value must be considered. “Resale enhancement is a huge benefit oil analysis brings to the table,” Betner says. “Having an electronic summary of the oil sampling results over the vehicle's life can raise its value by $3,000 to $4,000 if it's got a good oil sampling history.”
These are but some of the ways refuse fleets can benefit from a solid oil analysis program, BP's Edmond says. “It creates a ‘line of sight’ for the fleet manager, so they can literally see what's happening to the truck, both past and present, thus helping them make adjustments so it'll stay up and running in the future,” she says.
Sean Kilcarr is senior editor of Fleet Owner, a sister publication of Waste Age.