Search Results

Diesel particulate filters are remarkably efficient in reducing emissions of particulate matter from heavy-duty diesel engines. However, their efficiency and performance are negatively impacted by contaminants derived from consumed engine lubricant. This accumulation of incombustible ash imparts a fuel economy penalty due to increased system backpressure and demand for more frequent regeneration events. This study documents a systematic evaluation of lubricant impacts on DPF ash loading, system performance, and fuel economy. A novel, ultra-low ash heavy-duty engine oil demonstrates significant advantages in aged systems when compared to tests using conventional lubricants. The ultra-low ash oil yields a significantly lower ash loading that is also more dense therefore offering extended DPF maintenance interval and potential for 3% fuel economy retention benefit. These advantages offer potential for significant reduction in cost to operate and maintain a DPF equipped engine.

Future regulations have put increased focus on reducing criteria pollutant emissions, improving engine efficiency, and ensuring these benefits are maintained for the useful life of the equipment. Engine builders continue to require improved lubricants as enablers to meet these regulatory requirements. Most recently, these improvements have focused on lower engine lubricant viscosity, improved oxidative stability, and constraints on lubricant additives that interfere with emission control system performance. This study quantifies the synergistic benefits derived from combining a renewable base oil with ultra-low ash additive technology to improve fuel economy retention (FER). These benefits derive from their inherently low volatility and high oxidative stability, which limits lubricant thickening and deposits that would otherwise degrade fuel efficiency over the life of the lubricant.

Fuel economy of internal combustion engines played an important role for engine designers for decades. For heavy duty diesel engines, over the last 10 to 15 years however, fuel economy has in some cases been sacrificed for exhaust gas emission optimizations. Now that the industry seems to have reached the point of diminishing returns in the area of reducing diesel exhaust gas emissions, the focus is back on fuel economy. This paper addresses the impact that diesel engine lubricants can have on improving fuel economy. The evaluations discussed in this paper are based on fuel economy measurements in a standardized laboratory engine test.