With 93 or better you'll notice a small difference. Advancing and jetting is always a good thing if done right. An advancer is $50, if your retjetting might as well advance it.
I got both too - I noticed more power off the line.
The guys at Factory Pro said to run 93 so I do except when I can't get it. I have run 89-91 a few times on trips out west where 93 wasn't available without any problems.
A forum community dedicated to all Kawasaki motorcycles including the ZX-6R, KLR 650, Ninja 250, Ninja 250R, and Vulcan. Come join the discussion about performance, modifications, troubleshooting, maintenance, and more!