I have an 06 R1, and whenever I ran synthetic oil it seemed to make a bunch of noise at startup and while running, yamahas seem to make a lot of noise anyway. So what I do is I run half and half, half synthetic and half conventional, usually mobil 1 mixed with valvoline 20w50 motorcycle oil, the R1 Runs great and the noise level is very low compared to what most R1's make. If anyone else has a quiet running R1 id like to know what oil you run? ps I am in no way saying R1's arent a great bike, they just seem like the make more noise then the others, am I wrong?