Looking at some oil for my 04 Honda CBR600RR, I usually use Mobil-1 10W40 4T, recently the priced was raised, so naturally Castrol racing 4T came to mind at $8 a quart vs 10+ for mobil-1 nowadays. Only difference I could find is Mobil1 is rated API SN+ whereas the Castrol is API SL which is a older rating. Maybe I'm splitting hairs here..... especially since the bikes original rating was API SJ JASO 903 lol I'm pretty frugal and can't justify buying Motul 300v or 7100.