The engine oil capacity for a 1997 Porsche Boxster is 9.5quarts.
8.25 Litres with filter change too.
8 litres
9.5 US Quarts
20/40
I'm not sure on the weight but always check your owners manuel and always use 100% synthetic.
8 litres
10,000,000 of 5w/40
Mobil 1
hi moible 1 grade 0w-40
Factory fill is Mobil 1 Synthetic 0W40 European car formula. You'll need to look in the owner's manual for capacity and change volume.
Well, you can put the thicker oil in there, but it won't do much good for big end wear.