The latest modern engines operate at extremes of temperature and often allow longer service intervals. Without the right oil, this puts stress on engine parts and can lead to reduced responsiveness and poorer performance.
What is Shear?
The hot, stressful environment of a modern engine can literally tear normal oils to pieces. This action is known as shearing. If oils shear they lose viscosity and this can expose an engine to more friction and wear..

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| Shell Helix Ultra: Oil molecules resist being torn apart by shear forces. Viscosity and engine protection are maintained. | A normal mineral oil: Oil molecules can be torn apart by shear forces. Viscosity is reduced and friction and wear increases. |