This paper traces the development of lubricants for Diesel engine and heavy duty service from the time the mobile Diesel became a production entity in this country.
Beginning with a background of lubricants found acceptable for large Diesel engines in marine and stationary service, the trend in the supply of lubricants in subsequent automotive practices in the early 1930's led to difficulties in ring sticking, bearing corrosion and cylinder scuffing in the moderate speed, heavy duty engine seeking commercial favor at that time.
The attempts to solve these problems, both as to engine improvements and lubricant selection, are reviewed historically. The logical development of additive oils followed the pattern of alloy steel achievements.
The progress of additive effectiveness is sketched from applications as emergency drastic purging mediums to the constantly abiding aid of additive oils in maintaining the blood stream of lubrication in extended useful condition for the purpose of prolonging engine life.
Side by side with improved engine performance the pace of lubricant development has kept step. The war emergency found additive oils available to serve the urgency of heavy duty service in war and led to the Ordnance Approval Program. The struggle with higher sulphur fuels and the necessity for burning fuels of higher end point have challenged lubricant development to the achievement of Series 2 oils and Supplement 1 oils. Further progress awaits improvement in the 2-104B specification oils.
The past has witnessed the fruits of research by the cooperative efforts of the engine and petroleum industries; the future unfolds newer problems demanding the continued effectiveness of these constructive exchanges through cooperative agencies.