[Nathan5678]

ok time to change my oil but not sure what brand or viscosity oil to use. Should I try a synthetic? I am good with cars but still new to this whole boat thing. Any advice will be helpful its starting to get warm in Vegas and it's almost time to take the boat out.

Nathan
1998 Shabah 180 le 4.3l

[ggrims]

40 weight is good for 50 degrees air tempurature and over and was recommended in the Mercruiser manual, this was from a 1992 manual but I dont think this has changed much. Stay away from multi viscosity oils as you dont use a boat in extreme tempuature changes . I highly reccomend synthetic and only a pure synthetic as Mobil 1. Others are a blend or a synthetic made from regular oil. The best indicator for anti wear propoerties for synthetic is that most auto companies urge against the use of synthetics until a engine is broken in as they will keep the engine parts from wearing in correctly. If you only do your oil once a year go for the extra 20 bucks.

[mikeyt]

And i use 25W-40 semi synthetic in my 4.3L .....dont see the need for synthetics and particularly their cost in an older motor.