Do not use cheap oil if you care about your bike. I use fully synthetic motul oil and my gearbox is much more quiet and shifts better (still is a **** into 2gear though) proud owner of a 1999 r6 since 1999 :)got 40000+ km on it and got original clutch and always used the best oil i can get and change it every 5000km or so and the filter and it has had a hard life but only one failiure when the 2 gear died but that was a factory flaw got replaced under warranty :)