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kinematic viscosity
- Thread starter bsfc9
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Assuming you are referring to SAE Viscosity Grades for Engine Oils (SAE J300) there is no such thing as 0 or 5 grades. What there is is 0W and 5W. W grades are defined by their low temperature performance (as gauged in the Cold Crank Simulator and Mini Rotary Viscometer tests). Both grades require a minimum Kinematic viscosity at 100 C of 3.8 cSt, but have different low temperature requirements.
Non Winter grades are characterized by their Kv100 and High Temperature High Shear rate viscosities and don't require low T testing. Multigrades require both.
I haven't ever heard of commercial W-grade monograde products, but for example if one had a lubricant with Kv100 of 3.9 then it could be a 0W or a 5W monograde depending on its low T performance. It would not be a 0W-20 or 5W-20 because those require both the applicable low T performance AND Kv100 of 5.6-9.3 cSt (along with HTHS at least 2.6 cP).
Understanding viscosity behaviors and specifications can be confusing, and that's a big reason why the SAE grading system has been so widely adopted.
Non Winter grades are characterized by their Kv100 and High Temperature High Shear rate viscosities and don't require low T testing. Multigrades require both.
I haven't ever heard of commercial W-grade monograde products, but for example if one had a lubricant with Kv100 of 3.9 then it could be a 0W or a 5W monograde depending on its low T performance. It would not be a 0W-20 or 5W-20 because those require both the applicable low T performance AND Kv100 of 5.6-9.3 cSt (along with HTHS at least 2.6 cP).
Understanding viscosity behaviors and specifications can be confusing, and that's a big reason why the SAE grading system has been so widely adopted.
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