At FS , we feel the best way to gauge a lubricant ’ s level of performance is to put the oil into an in-field application and closely monitor the results . If you have read this newsletter in the past , you are already familiar with our million-mile teardown of Dave Marti ’ s Peterbilt truck . Dave had only used FS Dieselex Gold and Suprex Gold ESP in his truck , and we paid for an overhaul to see what the engine looked like inside . We were very pleased with the results . This time we took it a step further and overhauled an “ off-highway ” diesel engine that was really put through the stresses .
The Test : Traditionally , off-highway customers are best known for using an SAE 15W-40 API CK-4 diesel engine oil . However , in this trial , we wanted to put additional stress on the oil to test our formulation ’ s capabilities to protect the engine . We chose to test an SAE 10W-30 API FA-4 oil in an “ offhighway ” application , even though it was formulated and intended to be used in less stressful , on-road applications . Running an SAE 10W-30 compared to a traditional 15W-40 means the oil flows quicker at colder temperatures ( 10W ) and offers better fuel economy at operating temperatures ( 30 ). But the benefits of a thinner viscosity oil and reduced fluid film potentially could be offset by inadequate wear protection . While an API FA-4 category oil is not fully backwards compatible and is not expected to grow anytime soon in the off-highway marketplace , we simply put this field demonstration together to determine the formulation ’ s wear protection capabilities in a stressful off-road environment .
The Trial : The trial was conducted at a concrete operation . Concrete operations can be one of the toughest environments for engine oil due to a higher level of contaminants , higher heat , increased idle time , and excessive load . The unit
overhauled was a Kenworth with a 2015 Cummins ISX inline 6-cylinder , 12.0 L , 350 HP diesel engine . It was turbocharged and fully equipped with EGR , DPF , and SCR . At the time of the teardown , it had 10,601 hours on the engine . Oil drain intervals were conducted every 900 hours , and the unit spent 51 % of its operating time idling .
The Results : Along with our additive supplier , we were extremely pleased with the initial looks at the engine . Not only was it incredibly clean , but wear was minimal . Check out below some of the key engine components from the engine , including the pistons , cylinder liners , and main bearings .
Pistons : Shown here are the pistons . After they were removed from the block , all rings were disassembled . Piston rings were free moving on all six pistons , and there were minimal signs of wear . There were no signs of deposits or soot buildup . Lesser oils can lead to high-temperature deposits that can cause piston ring sticking . Ultimately , sticking rings can lead to increased oil consumption and blow-by if the seal within the combustion chamber has been impacted .