I'm in Canada, and during the 10hour my dealer put 3L of 10w40 "bulk" oil for $18.00 in my sea-doo during the 10hour. I can pick up castrol gtx 10w40 for $19.99 or Castrol Syntec 5w40 for $24.99 (it's on sale reg. $38.99) both are 4.4L

The question is, what oil should I be using?? The manual says 5w40, but on a lot of threads on here and Seadooforum people say 10w40, and of course my dealer used 10w40!

Am I okay with Castrol GTX? It meets SM API requirements.

Just looked at the shop manual which states: Use XP-S 10W40 Mineral oil or XP-S 5w40 synthetic oil.