So you guys actually store your cars over the winter? As in you don't drive it for a few months? I live in an area with a typical midwest winter of snow, ice, and negative degrees, but when a dry day comes along...
Anyway, Porsche says 15,000 miles or one year on the changes, if I recall correctly. I've yet to drive my Boxster 15,000 miles in a year, so I just stick to annual changes of Syntec 5w40. Only done two, and they have both been in the spring. Changing the oil before storage is a probably good idea if your storage period is longer than a month or so. Otherwise, I wouldn't worry about it. What I'd do instead is drive it more often.
