Synthetic oil - Safe?

[Yablokov]

lo guys =)

so the big 3k miles is upon me, and i have decided to start using synthetic oil.

my buddy told me that i should just change the oil like i would regularly.

but another buddy of mine told me it will screw up my engine if i dont fully flush out the old regular oil.

any help on whether it is really safe would be greatly appreciated!

thank you all again. =)