2018 年 63 巻 8 号 p. 563-572
This paper presents a study of the environmental performance impact of a comprehensive set of conventional viscosity lubricants and latest low viscosity lubricants, considering the use for average fuel economy passenger vehicle (118.1g-CO2/km in 2016). The vehicle was assumed to be equipped with either automatic transmission (AT) or contentiously variable transmission (CVT) with a lifetime mileage of 150 000km. Engine oil, transmission fluid as well as oil filter were identified as requiring servicing (replacement) in the maintenance phase. It was found that the analyzed engine oil, AT fluid and CVT fluid with different formulations show almost identical CO2 emissions per weight from the lubricants production, and the contribution of the oil filters and the transmission fluids to CO2 emissions in the maintenance phase accounts for over 20%. The latest low viscosity lubricants improved vehicle fuel economy by up to 4.0% compared to conventional viscosity lubricants. As a consequence, latest lubricants have the potential to save the vehicle life cycle CO2 emissions by up to 630kg-CO2 even when subtracting the produced CO2 emissions in the maintenance phase, with comparison of conventional viscosity lubricants.
