If your car has lived a long time on conventional oils, consider every 2000 miles (for the first 2 synthetic changes) doing the oil & filter. You will find initially the oil gets dirty quickly as the better cleaning properties of Synthetic Oils will pull dirt out quickly.
I remember when I first switched to synthetic in the Park Ave (bought used & it was run on conventional with 88k miles) first thing in the AM before starting, it was quite dirty on the bottom of dip stick (pan oil sediments) at 2000 miles.
The winter flow rate is better with synthetics as well. No carbon in syns as well.
I feel however that synthetics thin out too much when hot, and valve train noise may be apparent then. This is why I use LubeGard bio engine treatment. I can not say enough good things about it as it definately keeps the valve train quiet and smooth.
I recently pulled the valve cover'* to replace the gaskets, and this is with the first synthetic change at 2000 miles.
You can see still some small amount of dirt particles, this will clear over time with synthetics, and more frequent changes.
So if you can find the LubeGard..trust me it is worth the $10 or so...
(we want the engine to "purr" like a kitten!)