This post is a UK specific post.
In the UK synthetic oils for motorcycles are formulated differently to synthetic oils for cars. They use different friction additives.
If you use a car type oil in a machine with a wet clutch the additives can cause clutch slippage. Don't ask me how I know!***
A set of clutch plates fitted is an expensive penalty.
Now you'd think that returning to a motorcycle oil would cure the problem but it doesn't. Once the plates have been exposed
to the additives present in a car oil they remain contaminated and must be replaced, once again this depends on the specific additives.
To my knowledge there are no cars that have a wet clutch. So a synthetic oil designed for a motorcycle engine is formulated with this fact in mind.
I have no idea what additives are present in an oil in the US but I would however think that they have at least similar properties.
Just my twopence worth!"
Thus: If Can-Am specify a part-synthetic for the Spyders with the V-Twin motor then any similar oil which equals or exceeds
the makers spec.....it'll be fine. Yamaha (In the UK) also specify semi-synthetic in their big V-Twins. But don't make the very common
mistake of thinking that a full-synthetic oil is going to be better merely because it's all synthetic.
*** OK....I'll come clean! In 2007 I owned a Yamaha MT-01. A 1700cc V-Twin motor in a sports frame and I ruined the clutch by
using fully-synthetic oil for six months. The clutch slip got progressively worse under power and I toddled along to my dealer.
The workshop manager listened while I explained the ever worsening situation. Took the top off of the oil tank sniffed it and said
"You're using fully-synth. aren't you?" I nodded. "Don't!" he said. "You can have it back tomorrow when I've replaced the friction plates!"
Clearly keeping some of these Hi-Tech bikes on the road is a bit more involved than old British bikes like the Nortons
which I used to build!!
The MT-01 was never sold in the US......the motor in the Warrior was considerably different.
For those who want to see one here's a pic...click on it!