The longer an engine oil filter is in service, the more debris it will hold. Consequently, filter cartridges or elements and containers must be replaced or cleaned periodically.
Eventually, the filter can become completely obstructed, causing the oil filter’s bypass valve to open. This value ensures continued engine lubrication by diverting the oil from the primary filter onto the engine.
However, allowing this unfiltered oil to the crankshaft, engine bearings and other precision components can result in damage to critical internal engine components.
“Generally, the larger the element for any given filter design and engine, the longer it may remain in service before it must be replaced, say TMC officials, who advise following engine and/or filter manufacturer suggestions for appropriate change intervals with extended oil drain intervals.
Oil filter “capacity” describes the amount of debris an oil filter can remove and hold before it becomes obstructed and causes the filter’s bypass valve to open, say officials at Purolator Filters. “When this happens, the filter allows unfiltered oil to reach critical internal engine components, which is better than no oil at all, but not much.
“When choosing a replacement oil filter, one should be certain that the filter has sufficient capacity to capture and hold all the debris it’s likely to encounter during its service life.”
Another feature to consider when choosing an oil filter is efficiency, add the officials. Efficiency is a measure of the percentage of particles of a given size a filter is able to capture.
“Because engines are constantly evolving to align with emission regulations, fuel economy requirements and other environmental needs, advancements in filter technology are essential,” say technical officials at Fram. “Potential changes may include equipping the lubrication system with lower-viscosity oils and reinforcing the filter to handle stress from increased EGR (exhaust gas recirculation), extended change intervals and eco-conscious designs.
“Future filter designs also will require increased efficiency to protect the intricate clearances within the engine cavity.”
In addition, the officials say bypass filtration may become more prominent if soot-loading parameters are increased. A few filters, such as the Fram Wearguard TRT filter, already are taking a more proactive approach by incorporating timed-release additives into the oil to help maintain oil quality and lengthen oil-change intervals.
“The industry also has seen an increase in permanently mounted housings that use replaceable cartridge filters,” the officials say. “Similarly, a transition from platform to cartridge filters is likely to address environmental and disposal issues.”