Turbo oil sump plug socket size

Mike is correct on the Turbo oil sump 27mm.

I checked when I did an oil change on Wednesday.  As for the 915 oil supply drain plug it takes a 17mm open end wrench and is torques back to 18.5 ft pounds and safety wired to the top bolt after you drain the old oil and before you put the oil in. At least that is what I did.