Oil for 2004 wakesetter

[Susansetter]

My boat calls for 15W40 but all I can find is 15W40 for Diesel engines 

is this the same 15w40 to use in my gas engine wakesetter?

I can’t find “marine” 15w40 but I see marine in all kinds of other oils like 10w40

thanks for your input 

[Slayer]

I typically use Rotella in my Response.  I know others here use Delo.  Nothing wrong with the diesel oil so long as it’s the correct weight and carries a rating equal to that specified for your engine.

[MalibuNation]

My 2003 LS1 calls for 15W40 and I contacted the engine maker, Indmar, and they said it was ok to run Mobil 1 15W50 since I didn't want to void my warranty.

[electricjohn]

I've run 10w-40 for years.