my car has 44,000 on it at the moment. so if I decide to go synthetic can I just take it to walmart or any place that changes oil and ask them to do it? or do I need to have the pan completely flushed before adding synthetic?

 

You shouldn't have to flush anything. You should be able to change the oil like normal.

 

yeah i have 98k on my car and i use synthetic. it really depends on how your seals etc are. you might get more smoke with a synthetic at higher mileage because like tibby said, synthetic is composed of smaller particles. high milage oils are basically just more viscous. a thicker oil that it wont leak through your old (bad) seals. as for going back and forth between synthetic and dino oil, it doesnt matter. i personally will stick with synthetic. maybe if my car starts smoking then i will switch just for aesthetics B)
but after seeing the inside of an engine with synthetic vs with dino oil, im sold on synthetic. just remeber dino oil breaks down a lot quicker, and all that gunk its just building up inside!