Systems Assessment of Engine Oil Consumption Through Various Paths

Abstract

There is a rapid increase with application of turbochargers, variable valve timing engines, lubricant developments and other aspects that increase engine efficiency. As fuel consumption reduces through further engine developments, the engine lubricant oil consumption will become a larger contributor to engine exhaust emissions. Lubricant oil consumption can be through four systems within the turbocharged engine, which are: 1. PCV (positive crankcase ventilation), 2. VSS (valve stem seals), 3. Turbocharger, 4. PCU (power cylinder unit). Overall engine oil consumption is reliably quantified using the Tritium Tracer Oil Consumption Measurement System[1],[2] and with a gage repeatability and reproducibility study (R&R) of 6.4%. Test methods have been developed utilizing this measurement system that quantify the oil consumption contribution from the four different systems. This paper will summarize the techniques used and discuss potential challenges that new engine technologies pose on lube oil consumption.