oil changing frequency

[Cruzomatic]

How often to you change your engine and lower unit oil? I'm currently using volvo penta fully synthetic engine oil and lower unit lube in my 2005 5.0GL-E and SX-M sterndrive.

Manual says once a season and my dealer's service manager says to change it every 100hrs????

Your thoughts and opinions please.

 

[xxxflhrci]

Re: oil changing frequency

I change 'em both at the end of the season when I winterize. During summers when I run the boat more than a day or two a week, I will change the engine oil during mid-summer. My boat's a 1985 and still going strong.

 

[tashasdaddy]

Re: oil changing frequency

changing the oils is part of winterizing. before the first freeze, this makes sure there is not water to freeze and crack the lower unit. then if you put 100 hours on it during the season, change again. but always before the first freeze.