I'm no auto retard, but I really don't know that much about motor oil weight and grade.
Basically, what I need to know if this: what are the differences between 5W20 and 5W30.
Reason I ask is that my car's owner's manual specs 5W30, and the dealer put in 5W20 my last oil change.
What I do know is that 5W20 is thinner, so I would assume it flows better at very cold temps - common here in Canada.
Does it really matter what oil you run, as long as it's within reason of what Ford specifies?
Any help from oil experts, petroleum chemists, etc, out there would be greatly appreciated!
