Is it ok to switch back and forth between regular and synthetic oil on my 2008 g37s?

 

for what reason? just stick to one.

 

It would be wise to stick with one. If you use synthetic then stay with synthetic.

 

Why would you ever switch back and forth?

IBTL

 

its ok but pointless

 

just stick to synthetic

 

Mobil 1 specific but I'm sure it applies to all brands

Switching From Conventional Motor Oil to Mobil 1

 

Yes you can switch back and forth all you like - not going to hurt anything. My preference is like those mentioned here, once it's on a synthetic I stay with it until I figure I am getting rid of it - then it gets el cheapo whatever I can find.