Truth is that not very many recreational boats simply wear out the
engine.

There is not much that is mechanically different from a "newer" i/o
engine and one from 20 years ago.

Larry wrote:
"Eisboch" wrote in
news
My understanding is that some of the newer I/O engines based on the GM
350 block come with muti-viscosity oil recommendations. Those of your
vintage call for straight 30 weight, IIRC.

Eisboch




All those old charts have been replaced by:
http://www.mercurymarine.com/fueloil...mendation_faqs
so we can sell 'em new, special, most profitable, NMMA FC oils at the
dealerships, now, for $40/gallon.

Sure wish someone would take two Mercruisers, fill one with Mercury FC oil
and one with cheap, ol' Rotella T and drive 'em until they just fall apart
to see how special FC is at 4-6 times the price.....a realworld test.