No, people try to make it more complicated than it actually is.

i tried that actevo crap and my tranny started shifting hard. so i went back to crappy honda 10-40 and im at 15,000 miles.

FWIW Castrol Actevo is what Bill Blue uses in his klx's. I asked him what oil he recomended in the 351's He wasn't against using other oils, that's just what he uses.

Just use what the manual says and be done with it.

But manuals are just mfr's opinions:D

Dude Larry! That is awesome!!! Looks like the dichotomous key I use to repair the furnaces up here at work. Good stuff man....and probably true. ;)

Your right, but you can NEVER go wrong with using what the manual says. Any company does countless hours of testing on oils for engines they produce and under normal conditions it tells you what to use.:)

I know I was just supplying the answer any man should have ready to deploy in retort to "why dont you read the instructions" fired at him by his significant other.

Cheers, Jim

Been there many times myself, and my girlfriend always says didn't you learn your lesson last time you didn't read the instuctions!:D:D:D

Ever since Castrol's winning lawsuit against Mobil 1 regarding using the term "synthetic" to describe severely hydrocracked Group III oil, it has changed the term from a scientific term to a marketing term. MOST "synthetics" are not truly man-made molecules anymore. They are simply highly refined Petroleum. Don't wring your hands about that, though, because Group III oils perform within a gnat's eyelash of true man-made base molecules, at a fraction of the price. Don't worry about mixing anymore...unless you have some 20+ year old TRULY synthetic oil laying around...in which case I'd donate it to the local oil collection tank.

Also, you don't have to worry about friction modifiers hurting your wet clutch plates if you use a 15w-40, 15w-50, or 20w-50. Unless someone can point out an exception, I've NEVER seen any of these oils with an "Energy Conserving" label...that label denotes some friction modifier additives that could potentially mess with the clutch pack...ALTHOUGH, I've known many people that have used Energy Conserving oils in wet clutches, and they didn't have problems. I'd avoid them, though...they tend to be too thin for most motorcycle uses anyway.