Posts Tagged: oil film

Understanding Oil Viscosity: A Guide for Car Owners

Exploring the Importance of Oil Viscosity Modern motor oil is multi-viscosity. So, it has a slower flow rate when it’s cold and a faster flow rate when it’s hot. That’s why all multi-grade motor oils show two numbers. The first number, the one in front of the “W” (stands for Winter, not Wax), represents the oil’s viscosity at 0°F -17.8°C (its cold start performance). The second number, after the dash (—) represents the oil’s viscosity at 212°F  (100°C). So a multi-grade oil viscosity may be shown as 0W-16, 0W-20, 5W-20, … Read More