Motor oil

[Cat nap2]

I have a 25hp Honda outboard on my sailboat. It' s an old engine in good shape.
I use regular oil now.
I was wondering if going to synthetic oil would bee an a vantage or possibly cause problems or a waste of money ??
Thanks. cat Nap

[thomm225]

Originally Posted by Cat nap2

I have a 25hp Honda outboard on my sailboat. It' s an old engine in good shape.
I use regular oil now.
I was wondering if going to synthetic oil would bee an a vantage or possibly cause problems or a waste of money ??
Thanks. cat Nap

The "regular" oils are so goods these days it probably doesn't matter. My 2011 5 hp 4 stroke which is the outboard on my sailboat uses 10W-30 regular

[a64pilot]

A good synthetic will reduce wear a little, will not sludge or varnish, or maybe I should say will sludge and varnish less, and it will cost more. It should also go for longer intervals between changes.

However for most motors the best thing you can do for longevity is to use a good grade of regular oil, but change it more often. The money difference is negligible.

[Attikos]

Originally Posted by a64pilot

A good synthetic will reduce wear a little, will not sludge or varnish, or maybe I should say will sludge and varnish less, and it will cost more. It should also go for longer intervals between changes.

However for most motors the best thing you can do for longevity is to use a good grade of regular oil, but change it more often. The money difference is negligible.

This is straight question, nothing more: Why would it be better to use regular oil more frequently than standard than to use synthetic oil more frequently than standard? If the latter works better, then it would seem it would be the best choice, other things being equal.

[Empty Pockets]

Older engine+synthetic oil=leaks
Regular oil is fine. As mentioned, changing it is important.