H hattaresguy Joined Jun 1, 2011 Messages 7,180 Location CT Nov 4, 2014 #21 Marine motors are not terrible picky about oil. For Mercruisers any 15w40 will do, or you can use their own brand which I think is a 20w40. 10w30 is good for most 4 stroke outboards. Last edited: Nov 4, 2014
Marine motors are not terrible picky about oil. For Mercruisers any 15w40 will do, or you can use their own brand which I think is a 20w40. 10w30 is good for most 4 stroke outboards.