Stupid question, but I've learned here that some things are counter-intuitive.

I'll be using a 3/8 oil pan fitting. Does it make any sense to go w/ 1/2" drain flange and 1/2" oil drain line?

Does liquid only flow as fast as its narrowest point (the 3/8 pan fitting)?

 

From my limited knowledge (I'm a computer engineer) of fluids I would say using a the 1/2" line will give you better flow, but I don't think you need the added flow. If I'm correct there shouldn't be enough oil coming out the drain to warrant the bigger line.

 

you already answered your own question!!

 

Either one will work fine.
Stephanie