There's a MAJOR difference between oil lubrication and shear capacity. Engines fail when the oil is insufficient to provide a fluid bearing between the crank.
I disagree to a certain extent. Those are only two of oils functions. The most important is to provide a fluid bearing.Quote:
Motor oil is one of the most important fluids in your vehicle. The purpose of motor oil is to reduce friction and keep a vehicle's engine clean and corrosion-free
- Provide a hydraulic wedge for the fluid bearings
- Lubrication
- Cooling
- Cleaning
This is the first thing we learned in auto shop.
http://www.bearingsindustry.com/Images/fluid_film.jpg