Reduction of fuel consumption and pollutant emissions are key factors in the current development of powertrains. Engine oil has proven to be an efficient lever for improving fuel economy. The full potential of a low viscosity lubricant could be achieved by a shift towards formulations with low viscosity, high volatility base oils. However, there is a concern that this might increase oil consumption and limit long oil drain intervals.
This article deals with the engine lubricant contribution to oil and particle emissions. A series of 0W-12 oil prototypes have been evaluated both within laboratory measurements and on a modern turbocharged direct injection gasoline engine. Correlation between oil emission and engine oil properties will be presented.
The impact of engine oil on particle emissions has also been investigated under different engine operating conditions. A focus on particle size distribution demonstrates the relevance of transient driving conditions to the formation of unregulated emissions. Time-resolved measurement of a dynamic driving cycle provides a valuable insight to achieving additional emission reduction under real drive conditions.
