While I'm pretty careful with fluid changes, I change the oil in my 986 every 2 or 3 years. Only drive it maybe 1000 miles per year and it has nearly 10 quarts of M1 0w-40 so I'm not too concerned with changing it. But after reading here and wings&wheels suggestion, maybe I'll change it this spring when I bring it out instead of waiting until the fall like I was planning.