Multi Grade Oil

Table 4-162 Composition, Viscosity and SAE Specification of Multi Grade Oils ...

Lubricant additive, usually a high molecular-weight polymer, that reduces the tendency of an oil to change viscosity with temperature. Multi-grade oils, which provide effective lubrication over a broad temperature range, usually contain V.I. improvers. 

Manufacturers and other bodies have issued their own designations, which may be encountered occasionally. Most important is the US Military specification MIL-L-2105D (which replaced M1L-L-2105C) corresponding to API GL-5, and introduced approval for multi-grade gear oils. 

All water used is 18 Mil de-ionized water polished by a Simplicity ion exchange system available from Millipore Coiporation, USA. Trace Metal Grade sulfuric, nitric, and perchloric acids that were used in the procedures are available from Fisher Scientific, Pittsburgh, Peimsylvania, USA. Commercially prepared, multi-element, aqueous ICP-AES standards and the blank acid matrix were obtained from VHG Labs, Inc., Manchester, New Hampshire, USA. The multi-element, oil standards used for validation are available from Conostan Division, Conoco Specialty Products, Ponca City, Oklahoma, USA. 

OIL, MULTI-GRADE - An oil having relative little change in viscosity over a specified temperature range. 

To provide a mechanism of gellation for petroleum-based greases and encapsulants. Related to this, block copolymers provide viscosity index improvement in multi-grade lubricating oils. Tri-block copolymers... 

Viscosity Index Improver Viscosity index improvers, which can be present in multi-grade lubricating oils, can bias measurements. However, the biases can be reduced to negligible proportion by using the specified solvent-to-sample dilution and an internal standard. 

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