Experimental study on oil dilution under cold starts and its impact on oil quality
2022-01-0633
03/29/2022
- Event
- Content
- Oil dilution caused by fuel and water have been widely reported in modern Turbo-charged Gasoline direct injection (TGDI) engines, especially for those equipped with hybrid electric vehicles (HEVs). However, there is a lack of a systematic investigation on its causes and its impacts on oil quality. In the present study, a group of engine operation points based on the data from drum tests were selected and tested in an engine bench over different durations. The coolant temperature was fixed in each test, ranging from 30℃ to 90℃. Also, the effects of frequent engine start/stop and continuously engine operation were compared. It is found that the oil dilution level by fuel presents a good linear relationship with engine speed, torque and coolant temperature for the given cases while the oil dilution by water is negatively related with engine speed. The frequent start/stop could enhance the oil dilution by water, leading to the oil emulsification. The time for the recovery from the oil dilution by water is faster by an order of magnitude than that from oil dilution by fuel. Generally, every 1% increase in the level of oil dilution by fuel could improve the fuel economy by 0.2%. The oil dilution could cause a decrease in total acid number (TAN) and total base number (TBN).
- Citation
- Tan, Z., Li, Y., Xu, H., and Shuai, S., "Experimental study on oil dilution under cold starts and its impact on oil quality," SAE Technical Paper 2022-01-0633, 2022, .