One other consideration for my fellow 1.8T owners: According to a VW tech, VWoA recently issued a TSB which disqualifies all of us DIY oil changers from the 8-year sludge warranty. Since I run the oversize filter with Mobil 1 0W-40 on a 3K mile / 5K km OCI, I really don't worry about sludge, even with my wife's typical urban driving.