It seems that for some boats (at least mine anyway) 30 wt is preferred over
multi-viscosity oils, but if you cannot find 30 wt, then 20-50 works well.
Whtever you do, you want to check your manual and see what is allowed. My
manual says that 20-50 is okay and even 10-40 is okay. It also recommends
synthetic oil over conventional oil. Using conventional oil will not void
the warranty though.

Sometimes I cannot find 30 wt in a synthetic so I will use a 20-50 synthetic
instead of going to a 30 wt conventional because that will protect my engine
better.


"WaIIy" wrote in message
...

I understand that, I was wondering about 20-50 vs 30wt


On Wed, 17 Dec 2003 18:19:40 -0500, "Frank Taylor, Jr."
wrote:

30 wt refers to the viscosity charactersitics of the oil. It can still
be
either conventional or synthetic. As a matter of fact, Volvo makes a
straight 30 wt synthetic oil for its marine engines.


"WaIIy" wrote in message
.. .
On 16 Dec 2003 17:09:51 -0800, (Bear) wrote:

(Bear) revised earlier message
.com...

'97 Chapparal w/ a Volvo-Penta 5.7L Carb w/ SX Outdrive

Questions:

1) Volvo pushes synthetics for crankcase and outdrive, yet all the
boat places around me (Austin - San Antonio) said to use regular
20w-50 motor oil in crankcase and non-suynthetic in outdrive...
Of course they said to change every 100 hours or per season.
Experience / Opinions?

2) Any thoughts / experience on spark plugs for this motor???

Thanks!

Hmmm, the people I talk to in Ohio say to use straight 30 wt in my
1989
5.7.