I did run castrol 10w40 in the r6, good stuff. kinda bummed here, no one local stocks the 20w50 in synthetic like my bike calls for might have to run non-synthetic oil, I can get valvoline or castrol. AND btw, I was looking at oil at the pony, and they had alot of "synthetic blend" oil, sounded interesting but since its not available locally I didn't get it.