OP - You say you can get free 20w50 syn? If so use it in all three spots. It won't hurt a damn thing.

 

Buy a 30k bike and worry about saving 50 bucks to put free oil in it...cracks me up every time. It's your bike put whatever you want in it.

 

Heck, it might even work in the brake lines. Save another 2 bucks.

 

I remember someone putting automatic transmission fluid in the brake reservoir of a Ford truck. It wasn't cost effective.

 

Started running Mobil 15W-50 synth in the bike (twin cam) after doing a lot of reading on this forum and others. Just the main, not the primary or tranny.

 

For my FLHTCUI the owner manual says to use diesel oil if the motorcycle oil is not available. This lead me to an in-depth research of the difference between oil for gasoline engines and Diesel engines.
I would definitely use motorcycle oil as recommended and the suggested diesel oil if in a pinch.
But it’s your bike.

 

I suspect this may be true. But also suspect most people don't put enough miles total on the engine to care. That said I run a vtwin oil. But I am probably wasting money. But not like mobil 1 is cheap.

 

Call me crazy (Not "the" Crazy) but I'm gonna go out on a limb here and say this looks like an oil thread.

Or were you all expecting.......

 

What did they do before they have all the additives? They ran car oil in their motorcycles

 

Dude, and they ALWAYS deliver!