Best oil for F90

[rajuncajun]

Some charter captain buddies of mine swear by Amsoil for their Yamaha 4 strokes,some use Mobil 1.
Any input here would be great,time to get the flat boat ready for catching season.

[CatCam]

As long as they meet the Service rating it is all personal preference. Mine is a 2004 F90, the Marine designation for 4-stroke oils were not out yet so it was just the API Designation "SJ" oil. I've not heard of any oil related failures on these motors with anyone using synthetic or conventional oil.

I've used Penzoil Platinum full synthetic since day one.....10W-40, no problems here and I'm probably in your same geographical area per your "rajuncajun" call name.

[Saltfever]

Some charter captain buddies of mine swear by Amsoil for their Yamaha 4 strokes,some use Mobil 1.
Any input here would be great,time to get the flat boat ready for catching season.

We started using Amsoil a couple years ago in all of our vehicles and the boat. Love it.......

[CatCam]

We started using Amsoil a couple years ago in all of our vehicles and the boat. Love it.......

what is the big difference over what you were using before? Just curious. IMHO I think it is like the feeling that my truck runs better when it's clean!