I bought a used '16 KTM Duke 390, this bike had +1300 miles on it when I bought it. Have since run 400, oil was low and dark, I went ahead changed the oil saw some metal shavings which from what I'm told and read that's normal for the first couple oil changes. The owner's manual calls for Motorex Formula 4T 15W/50. My question being does anybody have experience with the Shell Rotella® T6 Full Synthetic Diesel Oil? With this bike being basically a souped-up dirt bike IC folks online running Shell 5w-40 in the their street bikes. If not what's the best choice? The bikes motor is bone stock as of now, but I see a need for a PCV/remapping down the road and open the air box + a better air filter to smooth out the power curve.