Long Drain/Fuel Efficient Engine Oils Based on the ZDTP Substitute Additive Technologhy 2003-01-2003
Zinc dialkylphosphate (ZP), a sulfur free analogue of Zinc dialkyldithiophosphate (ZDTP) has been synthesized and tested for engine oil application. The sulfur free engine oil based on ZP showed excellent TBN retention and engine cleanliness in several engine tests which were operated at low and high temperatures. A prototype low phosphorus (0.05%) and low sulfated ash (0.5%) engine oil exhibited even better longer drain performance than a fully synthetic engine oil containing 0.1% P and 1.1% sulfated ash. Thus, zinc dialkylphosphate can be a promising candidate as a ZDTP substitute for future catalyst system compatible engine oil.