I've changed the oil on two STi's at less then 10 miles, as the ones that come with port installed guage pods still need to have the oil temp sensor installed. I think if the oil was treated or special in some way, we would not be doing this. Also I changed my oil at about 1000 miles, and it appeared to have moisture in it. Even though it only had 1k on it, it had sat at the dealer for 8 months and who knows how long since the oil was poured in initally. I've done fleet service, they change every 3 months regardless of mileage. btw, I also switched to mobil 1 at around 5k.