For instance, oil with a 10W-30 grade thickens faster than oil with a 10W-40 grade. This number represents the oil’s resistance to thinning at high temperatures. The number after the “W” indicates oil viscosity at 212 degrees Fahrenheit (100 degrees Celsius). A car used in a very hot climate would need a higher number to ensure the oil does not thin too much. An engine in a colder climate where engine oil tends to become thicker because of the low temperatures would benefit from 0W or 5W. A 5W-30 engine oil will become thinner at low temperatures than a 10W-30 grade, but will still flow slower than a 0W-30 grade. The lower the number, the less the oil thickens in cold weather. The number that precedes the "W" indicates the fluid's flow at 0 degrees Fahrenheit (-17.8 degrees Celsius). In relation to engine oil, this is noted down using the usual "XW-XX" notation. This is a measure of a fluid's resistance to flow. Which factors should you take into account when choosing the right engine oil? Viscosity OEMs, moreover, are adjusting their lubrication instructions faster and faster to comply with the need for green and fuel-saving alternatives. Engines often need a different viscosity depending on the operating conditions. 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.Often, a manufacturer will suggest one or more viscosity values for an engine such as 5W-20 or 5W-30 based on different factors including the temperature and load. 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 |