![]() The ashless dispersant grades contain additives, one of which has a viscosity stabilizing effect that removes the tendency of the oil to thin out at high oil temperatures and thicken at low oil temperatures. W oils are of the ashless type and are still in use. The viscosity index (VI) is an arbitrary, unitless measure of a fluids change in viscosity relative to temperature change. To overcome the disadvantages of harmful combustion chamber deposits, a nonmetallic (i.e., non-ash forming, polymeric) additive was developed that was incorporated in blends of selected mineral oil base stocks. In most engines, the performance of these oils with respect to oxidation and thermal stability was excellent, but the combustion chambers of the majority of engines could not tolerate the presence of the ash deposits derived from these metal-containing additives. Equivalent viscosities for 100 & 210F are shown SAE 90 to 250 and 20 to 50 specified at 100C. ISO are specified at 40C AGMA are specified at 40C SAE 75w, 80w, 85, 5w, & 10w specified at low temperature. While the VI has no units of measure, it is well known that the viscosity index of a conventional mineral oil is between 95 to 100. The first additives incorporated in straight mineral piston engine oils were based on the metallic salts of barium and calcium. Viscosities based on 96 VI single grade oils. ![]() Demand for oils with higher degrees of thermal and oxidation stability necessitated fortifying them with the addition of small quantities of nonpetroleum materials. RENOLIN B HVI high-quality products are used as hydraulic oil and as lubricating oil for various applications like bearings. It may be recalled that in our examination of the animal reaction to mineral oils we have adopted two major procedures, viz. ![]()
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