Question: what is the difference in car engine oils?
Answer: Viscosity, at its most basic, is a fluid's resistance to flow. ... So 5W-30 viscosity engine oil thickens less in the cold than a 10W-30, but more than a 0W-30. An engine in a colder climate, where motor oil tends to thicken because of lower temperatures, would benefit from 0W or 5W viscosity.