There are two main reasons. The first is that synthetic works so well that
there is no burnishing in of the parts to seat the rings, etc. This will
result in the engine using oil in the long run.
The second is that with the extended drain periods that most people use
with these oils, there is no initial drain after a thousand miles or so to
drain out all the loose shavings, dust, and dirt that the oil washes out.
On new modern engines, the factory machining capabilities today are so good
that they really don't need a "break in" like older engines did when they
were new. The main thing now is to wash out the crud, and I bet even the
Corvettes need to be drained after a thousand miles or so the first time.
>I've heard for the longest time that synthetic oil should not be used during
>an engine's initial break in, but I've just read that GM has been putting
>mobil 1 synthetic in Corvettes right off the asembly line since 1992! What's
>the deal here and what's the real nitty-gritty scientific reason for using
>natural over synthetic for break-in?
>50 & 53 GMC 1/2 tons
>48 GMC 3/4 ton
>oletrucks is devoted to Chevy and GM trucks built between 1941 and 1959
oletrucks is devoted to Chevy and GM trucks built between 1941 and 1959