What the Heck is Shear Stability in Motor Oil?

There is a lot of technical jargon in the motor oil industry and somehow these guys think people understand what they are saying when they talk about things like “shear stability”.  People like to hear and talk about things like extra horsepower and better engine protection…not so much “shear stability”.  How does shear stability relate to added horsepower and better engine protection anyway?  Excellent question, I’d say.

I am going to get a little abstract here to help understand what is going on at a molecular level.  The hotter the motor oil, the thinner the motor oil.  Scary but true, when conventional oil heats up it gets so thin that it doesn’t do its job properly anymore.  So, a VI (viscosity improver) is added to stop the oil from becoming to thin.  When temperatures in the engine soar, the VI keeps the oil thicker so that it can still protect the engine…but here’s the kicker…

If you could zoom in and look at motor oil with an electron microscope you could visualize VI as coils of spaghetti.  The spaghetti coils are compact, bouncy, wound up and move around each other with ease when the VI is cold.  But once the VI gets hot then the coils unwind, elongate, and they aren’t moving around each other so easily anymore.  This makes the fluid move around less freely and counteracts the thinning of the base oil.

If cheap VI improvers are used the oil will wear out faster in your engine.  The shearing effects of the moving parts in the engine rip the VI improver apart and you end up with oil thinning.  You’re left with tiny pieces of spaghetti molecules that let the oil flow like water at high temps.

This could mean a little bit of cheap horsepower with the terrible cost of loss of engine protection…  more engine wear.

The shear stability of an oil indicates the lifetime of the oil’s protective attributes due to its viscosity.  Your oil won’t offer much protection if it has a low shear stability.  The higher the shear stability is, the longer your oil will be protecting your engine.

To check out where the top oils rank on the shear stability chart go grab the best motor oil review.You can see the comparisons of the top oils for yourself…where does your brand of oil fall on the shear stability chart?  Find out here when you check out the best motor oil review.

Hope that helps!


Related Blogs


Random Posts:


Similar Posts:


Leave a Reply

CommentLuv badge

This site uses KeywordLuv. Enter YourName@YourKeywords in the Name field to take advantage.

Security Code: