Im using NEO engine oil atm, 10W40 - so far I think its the best ive ever used, I came from using Motul 300V - its damn pricy (1x5L will cost you the same as 2x4L of 300V), but the car is as smooth as a dream and its still honey coloured after 3000ks. Supposedly you don't have to change this stuff until 10,000ks.. not that I'll be taking that chance, though.