Just did an oil change on a moderately modified E92 N54 335i today. This was previously my car that I sold to a good friend back in July, 2016. He changed the Hengst filter with a Mann sometime in February, 2018 but for some reason kept the oil in. The oil that I drained out has been in the crankcase for 4 years! It was GC 0W30. The filter was in service for 28 months. The oil was in service for 48 months and 7.2k miles/11.5k km. I didn't send the oil in for UOA though I probably should have. It was flat black and very runny, but no sludge. Mann HU816 looked good, pleats were getting wavy but end caps were still solid. Anyways replaced with WIX 57327XP and MM5W40 European formula (maybe Shell Helix Ultra 5W40?).