Engine lubricants performance ratings

All hydrocarbon oils react with oxygen upon exposure to air at sufficiently elevated temperatures for long periods of time. Over the range of temperatures developed in engine crankcase, the rate of oil oxidation has been found to double for every 20°F rise in temperature. Although all lubricating oil hydrocarbons are susceptible to oxidation, of more importance to engine performance are the oxidation products. Paraffinic hydrocarbons... 

This time limit is established in the Topical Report CENPD-201-A. Combustion Engineering will perform a test to verify the analysis in Appendix A. The component cooling water will be secured to the pump lubrication oil sumps and data taken so as to demonstrate the heat up rate of the oil sump up to a maximum sump temperature of 200 F. A test securing cooling water to the pump seals will also be performed to demonstrate the seals operability as detailed in Combustion Engineering Topical Report CENPD-201-A. In the remote possibility of a simultaneous loss of component cooling water to all reactor coolant pump motor assemblies, 30 minutes is adequate to secure the plant and maintain the normal coast down capabilities of the reactor coolant pump motor assemblies. 

The most common of the other specifications are those with the prefix MIL, issued by the US military authorities. M1L-L-2104E approximates to the API CE rating for diesel lubricants, although it also relates to petrol engines that require API SE performance. M1L-L-46152D covers oils for both diesel and petrol engines, and approximates to API SG/CC (Figure 52.5). 

Another important set of performance specifications is produced by the European Vehicle Manufacturers Association, known by its initials CCMC. The CCMC rating G-1 corresponds roughly to API SE, and G-2 to API SF. G-3 (comparable to M1L-L-46152B, for petrol engines only) covers fuel-efficient and light-viscosity lubricants... 

The ZDDP deterioration By reference to Table 6.10 and the case study 2 Evaluation of ZDDPs , in field tests of 56 passenger car vehicles (taxi cabs) and laboratory analysis of lubricating data were included viscosity, TBN, TAN, ZDDP (active), dispersants, oil consumption rate, engine deposits, camshaft and valve lifter wear. Which of the major ZDDPs and ZDDPs mixtures provide the best antiwear and antioxidant performance ... 

A6/B6 for use at extended drain intervals in high-performance petrol and diesel light vehicle engines designed for low-friction, low-viscosity lubricants with a high-temperature/high-shear rate viscosity of 2.9-3.5 mPa.s. 

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