[Chrome Bumper]

Stihl is nominally a 50:1 ratio as are 90%+ of the outboards. With outboards you can stretch it a bit if you don't operate at wide open throttle. If your motor is still under warrenty it probably requires TW-3 spec oil.

Synthetic is worth the bit of extra money. Buy it in bulk if you use a lot. I am a stilh fan, I wouldn't hesitate to use it in an outboard.

 

[Chrome Bumper]

There is zero proof that synthetic TCW-3 provides any more protection than regular oil.

Its the smoke and carbon build up from the conventionals I don't like. As soon as stihl has a four stroke chainsaw the 2 stroke oil goes in the trash.