[Spridgets] Question about oil - No LBC content

[David Booker]

I have used synthetic oil in my Frontier since it was new and intend to
continue, but just got something from my local dealer saying they will change
the oil & filter for $20. Obviously, this is not going to be synthetic. I have
never once in my life paid somebody to change the oil in any of my
vehicles...but it's real cold out there and I don't have a garage at the
moment. So I am ever so slightly tempted.

So, I have heard that you are not
supposed to go back and forth between synthetic and non-synthetic oil. Is this
true? I can't think of a reason it would be, but I'm no chemical engineer.
(tho I do play one on TV) ;-)

Thoughts? 

 - David