Introduction

The lubricating oils considered in this symposium are of an entirely new type and differ from the previous heavy-duty oils in that they contain from five to ten times as much additive. This is exemplified by the ash values of some of these oils which are above 2 per cent. The high-additive oils were developed primarily at the request of the Caterpillar Tractor Co. to meet a field condition involving severe operation of engines using high sulfur fuels. These oils are identified as “Series 2” oils and the Caterpillar experience with them is reported to be excellent. The excellent success with the Series 2 oils in Caterpillar engines has led investigators to determine if other problems in other engines could also be corrected by the use of these oils. This is the first time that actual adequate field service data on Series 2 oils have been presented publicly, and the papers and formal discussions will give a well-rounded presentation from the stand-points of both the equipment and lubricants manufacturers. In view of the relatively greater extent to which “dieselization” has taken place in the West as compared to other regions, and of the special problems encountered here, it is especially appropriate that this first symposium be held on the West Coast. In spite of the short time since introduction of these oils, a considerable background of results has been obtained, and these data are the basis for this symposium. It is unlikely that the results from the various laboratories will be in complete agreement, which should stimulate discussion and further experimentation progress. The exchanges of information in symposiums of this type have contributed to the solution of such problems in the past, and continued cooperative effort should be equally valuable in the future.