Misinformation about motor oil and when to change it abounds. Here's the truth about engine lubrication from your friends at Nissan of Meridian in Meridian, MS.
The 3,000-Mile Oil Change: Change your oil every 3,000 miles! That may have been true once. Today's lubricants remain effective for 10,000 or even 25,000 miles.
Synthetic Oils and Engine Leaks: Worn-out engine seals, not synthetic oil, cause leaks. Synthetic lubricants help to prolong engine seal life.
Synthetic and Conventional Oil Don't Mix: There are circumstances under which the blending of conventional and synthetic oil is ill-advised. Both motor lubricants are essentially the same thing. The difference is a higher quality base oil goes into making a synthetic oil. In most instances, it's safe to mix the two.
Changing Black Oil: Replace black oil immediately! Blackness indicates that your oil is keeping your engine clean. Your owner's manual is your best source for determining when the oil should be changed.