I use mobil 15w50 in my zx10... actually helped the shifting compared to MC oil that was being used...

Don't know if any of yall read sport rider.. high performance motorcycle mag.... but anyway, they tested a lot of different kind of oils, and the Mobil 15w50 full syn had the best results.... go figure huh... was in the April 06 magazine. Change oil and filter usually around 2000-2500 miles, sometimes sooner depending on driving.. I've got dang near 35,000 miles on my baby, and she still runs like a brand new one!!