Lubricants have been improved no less than the fuels, and no less importantly. The discovery of inhibitors against the oxida tion of gasoline was also important to the lubricating oils in use; and, if improved design of engines has required more of the fuel, it certainly increased the burden upon the lubricant—which has been met by extreme-pressure lubricants and other types essential to successful operation. Lubricating oil has been the subject of intensive research study. The old sulphuric-acid meth od of refining has been largely abandoned for the modern solvent refining methods capable of yielding oil of exceptional stability, and at the same time lowering manufacturing costs. Whereas previously unstable fractions were lost to sludge, under these methods all the oil is recoverable, and even the rejected fractions have been found to contain valuable hydrocarbons of the un saturated, or aromatic, type which may find their own place in commerce as the starting point of chemical synthesis. The development of propane and similar de-asphalting methods made possible the employment for lubricating oil manufacture, of crudes which might otherwise be regarded as too low in grade for any thing except fuel oil. The application of solvent and similar de waxing methods resulted also in an increased supply of lubricating oil of adequately low solidifying temperature, with consequently improved lubrication in cold weather, with easier engine starting and less cold-weather wear of engine parts.
Solvent-refining methods, both for improving oxidation stabil ity and viscosity-index characteristics, as well as for removing waxes, have been rapidly developed ; but research has also shown the possibility of obtaining similar results by the addition of certain synthetic substances for reducing the pour-point of petro leum oils which permit the attainment of the desired low-tempera ture fluidity without resorting to expensive very low-temperature de-waxing, and at the same time preserve in the oil all its desir able characteristics. Research continued in the attempt to improve the viscosity-temperature susceptibility characteristics, or fluidity at low temperatures, by the addition of various types of heavy synthetic oil. Corrosion inhibitors have been important factors in improvements in oils. Remarkable synthesis of lubri cating oils has been made from such diverse substances as paraffin wax and natural gas, an example of molecular rearrangement with a definite service in view.
The benefits to the motoring public resulting from research in lubricating oil include: (I) easier starting in cold weather; (2) lower consumption of lubricants per car-mile; (3) greater mile age from gasoline resulting from better sealing of the piston rings; (4) reduced wear on bearings and other moving parts, with resultant reduction in maintenance costs; and (5) less carbon formation, and as a result less frequent cleaning of piston and cylinder heads. An example of what better lubrication means may be found in the field of aviation. Superior oils produced by
extraction methods, and with suitable addition agents, have in creased the time of overhaul from oo-to-200 to 5oo-to-i,000 hours, and at the same time, have contributed to the smooth operation of the modern aeroplane engine. Because of hypoid gears with their extreme-pressure lubricants automobile manufac turers have been able to lower the body of the car, thereby secur ing greater safety and reduction in weight.
The use of these improved extreme-pressure lubricants and cut ting oils extends over into many manufacturing operations, for they permit greatly accelerated production speeds in the fabri cation of steels and the working of alloys hitherto impossible. Using these improved cutting oils the average machine shop with the same personnel and equipment can turn out at least i00% more work.
There has been much research in asphalt development, in co operation with highway engineers and paving technicians. Asphalt has been found more economical in first cost, maintenance, and improvement expense than other surface materials. Notwithstand ing the enviable position of the United States as compared with many other countries in the matter of thousands of miles of paved roads, it is not likely that the country's paving program will ever be completed, because there is always the question of secondary or farm-to-market roads and the necessity of rebuilding, straighten ing, resurfacing, and other factors of road improvement.
A field of great importance, which has scarcely been touched, is the production of solvents and many other chemicals from petroleum as the raw material. The availability in petroleum fractions of the molecules needed for this purpose is known, and these fractions are occurring in an increased number and variety. The American petroleum industry itself has entered the industrial chemical field through the utilization of available hydrocarbons for the manufacture of iso-propyl and the higher alcohols and their ethers and esthers, which have been produced from olefins available in the cracked gas. Synthetic ethyl alcohol and other members of the alcohol family of important solvents are deriva tives of petroleum through the synthetic route. By making avail Figures are before deducting reserves for depreciation, depletion, and amortization. Authority: American Petroleum Industries Committee.
able aliphatic hydrocarbons in large quantities, an aliphatic chemical industry has been built up which may rival in importance the aromatic chemical industry of which the products derived from coal-tar are the outstanding example.
The petroleum industry also has developed viscous oils and rub ber-like products from gaseous hydrocarbons. These polymers have material resistance to acids, alkalis, weathering and aging; and are used as coatings for all sorts of base materials. They are found useful in rubber compounds, improving the latter in many respects. There has also been made available a variety of synthetic resins made from oxidized hydrocarbons.