I went from Formula + to Syn3, because I have been convinced that synthetics out perform in most applications. But then I recalled from my Suzuki ridin' days that the friction modifiers found in motor oils do not do clutch plates any favors. I have since gone back to Formula+. In my case the clutch felt a lot smoother. I'd consider Spectro if it is strictly a gear oil with no friction modifiers.
I went from Formula + to Syn3, because I have been convinced that synthetics out perform in most applications. But then I recalled from my Suzuki ridin' days that the friction modifiers found in motor oils do not do clutch plates any favors. I have since gone back to Formula+. In my case the clutch felt a lot smoother. I'd consider Spectro if it is strictly a gear oil with no friction modifiers.
Thanks Glider, I see I was not clear on that. I use Formula + in the primary and trans now, and syn 3 in the engine. Prior to that i used Syn3 for everything, based on HD's specs.