Changes

Some say that switching from conventional oil to synthetic, particularly on high mileage engines, can cause an engine to leak. What is actually happening is that conventional oil creates build-up around seals that would normally be leaking. Synthetic removes this build-up and can begin to seep past seals. So what is actually happening is that synthetic oil is uncovering the leaky seals that already exist in the engine.

Conventional oils are recommended for approximately the first 1000 miles during engine break-in of a new or rebuilt engine. The ultra slippery nature of synthetic oils can cause the rings to fail to seat properly, or take much longer than they should.