[Formerly Steve Wilkinson]

Actually, the Boxster doesn't have a dry-sump system even though that's what Porsche calls it. Here's the full description from the shop manual: "To ensure reliable engine oil supply, the Boxster has an integrated dry-sump lubrication system without an external oil tank. The oil sump is in the bottom of the crankcase."

Sounds like a wet sump to me, which is also exactly what the schematic shows...I would credit the PAG marketing department with the phrase "dry sump," since it implies "better."

Capacity is indeed 9.25 U.S. quarts including the filter.