Viscosity engine oil

Table 1. Engine Oil Viscosity Classification SAE J300 (April 1997)a...

Caracciola, F. and McMillan, M. L. SAE Paper 790728, June 1979, "Effect of Engine Oil Viscosity on Low-Temperature Cranking, Starting, and Fuel Economy. ... 

J300 Engine Oil Viscosity Classification, revised May 2004 (Warrendale, PA Society of Automotive Engineers). 

McMillan, M.L. What should an engine oil viscosity system do . Opening Address at SAE Open Forum, Detroit, Michigan,... 

Oil viscosity grades have also been developed with suitable additives for use in a variety of specific appHcations in two-cycle engines, refrigeration and air conditioning, oil mist lubricators, low outdoor temperatures, instmments, and office machines as partially reflected in Table 3. Equipment manufacturers and lubricant suppHers provide recommendations for individual cases. 

Viscosity improvers are primarily used in multigrade automotive engine oils, automatic transmission oils, power steering fluids, and gear oils. They also find use in aircraft and some industrial hydrauHc fluids for low temperature use. 

Marine residual fuels bunker fuel oil Grades ISO RMA through RML marine residual fuel and bunker fuel are blended from components such as atmospheric resid, vacuum resid, visbreaker resid, FCC bottoms, low-grade distillate, and cracked components. Bunker fuel has a maximum viscosity of 550 cSt 122°F (50°C), density of 0.990 g/cc, and sediment of 0.1 wt%. ISO marine fuel oil viscosities range from 10 to 55 cSt 212°F (100°C). These fuels are used in slow-speed diesel engines and boilers. 

Higher boiling-point, less-volatile components in gasoline may not completely vaporize during cold weather startup of an engine. In the cylinder, the still liquid fuel components may flow past the the lubricant from the piston and cylinder walls and also lead to a reduction in the lubricating oil viscosity. Together, these two... 

We now turn to black oils. We consider those physical properties which are required for the reservoir engineering calculations known as material balance calculations. These properties are formation volume factor of oil, solution gas-oil ratio, total formation volume factor, coefficient of isothermal compressibility, and oil viscosity. Also, interfa-cial tension is discussed. 

Lubricating oil, like this automobile engine oil, consists primarily of high-molar-mass hydrocarbons. Their long chains coil about one another, giving the oil a high viscosity. 

SAE (Society of Automotive Engineers)—organization responsible for the establishment of many U.S. automotive and aviation standards, including the viscosity classifications of engine oils and gear oils. See SAE viscosity grades. 

SAE viscosity grades-engine oil classification system developed by the Society of Automotive Engineers (SAE), based on the measured viscosity of the oil at either -18°C (-0.4°F), using test method... 

Example Multigrade lubricating oils. The viscosity grading of some automotive engine oils is shown in the table below [389]. 

In a fully synthetic oil, there is almost certainly some mineral oil present. The chemical components used to manufacture the additive package and the viscosity index improver (VI) contain mineral oil. When all these aspects are considered, it is possible for a "fully synthetic" engine oil to surpass mineral oil (Shubkin, 1993). Synthetic oils fall into general ASTM classification (a) synthetic hydrocarbons (poly-a-olefins, alkylated aromatics, cycloaliphatics) (b) organic esters (dibasic acid esters, polyol esters, polyesters) (c) other fluids (polyalkylene glycols, phosphate esters, silicates, silicones, polyphenyl esters, fluorocarbons). 

Poly(a-olefins) or PAOs, polyol esters and diesters are now used in automotive and marine engine oils. To understand how an ester lubricates, it is important to consider its behavior in the different lubrication regimes, especially boundary lubrication when the properties of the bulk lubricant (e.g. viscosity) are of minor importance. The chemical properties of the lubricant responses under extreme conditions will become increasingly important. The polar ester will preferentially stick to the surface of metal when a small amount of ester is added to a low viscosity nonpolar fluid (PAO), (Randles, 1999 Spikes, 1999). When the two metal surfaces come closer together, the polar ester molecules stay in the contact zone. The use of fully synthetic engine oil formulations has produced some improvement in viscosity control and engine cleanliness in the piston and valve train areas over petroleum-based oils (Boehringer, 1975 Frame et ah, 1989 Kennedy, 1995 Lohuis and Harlow, 1985). 

This advantage is due to molecular structure and the lack of crystalline wax particles, present in some refined petroleum oils. Fully synthetic engine oil lubricants offer excellent low temperature flow and viscosity properties.(Demmin etal., 1992 Lakes, 1999). 

---