![]() “Viscous” therefore originally meant “sticky like birdlime”. Glue used to be extracted from the mistletoe for catching birds. The concept takes its name from the typically gooey sap that comes from mistletoe berries (viscum). Nearly all physical media and foodstuffs have a specific viscosity. Thin lubricating oils are mostly deemed to have low viscosity and thick lubricating oils are deemed to have high viscosity.īut viscosity isn’t just measured for lubricating oils or paints and adhesives. And the lower the viscosity, the thinner the oil. The higher the viscosity, the thicker the oil. Viscosity nowadays means a measurement of the flowability of a lubricating oil or hydraulic fluid. Several modern devices have been installed in the laboratory just for determining viscosity alone. OELCHECK principally assesses viscosity in oil samples at 40☌ and 100☌ and calculates the viscosity index from this. Since it can change when an oil is being used, it is one of the most fascinating and extensive topics in lubricant analytics. It is also dependent on temperature and can be infl uenced by special additives. It plays the decisive role in the choice of accompanying lubricant as it describes its fl uid characteristics. Viscosity is the most important physical characteristic of an oil. Other engines, including most older ones would not be well enough protected with these very thin oils.įor information about SAE 16 read our previous article The SAE 16 Viscosity Grade.The single most important physical characteristic of any oil And even when there will be actual products meeting these specs they will only be suitable for engines designed with these oils in mind. While these new viscosities certainly set the path for motor oil development for the time being you will not find any SAE 8 or SAE 12 oil on the shelves. Honda was the first automaker to request the introduction of these new grades after having completed successful tests using oils with similar parameters. These new viscosity grades allow the formulation and production of lubricants that enable better fuel economy. High-Shear-Rate Viscosity, cP at 150 ☌ min. Low-Shear-Rate Kinematic Viscosity (cSt) at 100 ☌ max. Low-Shear-Rate Kinematic Viscosity (cSt) at 100 ☌ min. Low-Temperature (☌) Pumping Viscosity, cP max with no yield stress Low-Temperature (☌) Cranking Viscosity cP max. ![]() The low shear rate KV limits for SAE 8, SAE 12 and SAE 16 overlap to allow greater flexibility in lubricant design. In case of SAE 12 the low shear rate KV must be in the 5.0 - 7.1 mm 2/s range, while the high shear rate viscosity must be 2.0 mPa*s or higher. For a motor oil to meet SAE 8 requirements its low shear rate kinematic viscosity at 100 ☌ must be between 4 and 6.1 mm 2/s while its high shear rate viscosity must be at least 1.7 mPa*s at 150 ☌. The new viscosity grades are SAE 8 and SAE 12 defining new limits for future engine oils built for even better fuel economy.īoth SAE 8 and SAE 12 are operating temperature viscosity grades so they have minimum and maximum limits regarding their low shear rate kinematic viscosity at 100 ☌ and minimum limits regarding their high shear rate viscosity at 150 ☌. On Januthe Society of Automotive Engineers, better known by its acronym as SAE added two new viscosity grades to its most popular viscosity classification system defined under the SAE J 300 standard. Introducing the SAE 8 and SAE 12 Viscosity Grades
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |