(JAXAshby) wrote in message ...
With all that, I don't see any reason that a 20w-40 or 20w-50
would not be a preferable choice to plain old SAE 20, 30, or 40 which are
all recommended in my 1987 manual.

operating weigh above recommendations can harm seals. thus using 20w-40 in
place of 20w doesn't do any good for lubing upon engine startup and can do some
harm when the engine is warm.

some people are under the mistaken impression that multi grade oils "thicken
up" as they warm up. they don't. they just thin out less as they warm up.

a 30w oil will keep its viscosity over a much broader temp range then
a multi weight oil. this is the reason for this recommendation. they
are also better for heavy load conditions, because once again load
creates heat and a 30 w oil will stick around better.

just to clarify jax a 5w-40 oil is 40 at rest/cold therefore will take
more time to pump anywhere being theoretically 25% thicker then a 30w
oil.
perhaps leave the vitriolic attacks at home for people that are just
trying to help. do some reading on oil viscosities is my
recommendation to you.

manufacturers dont make recommendations for no reason, follow them and
you will never have any trouble.
if you are having trouble finding a 30w oil any volvo dealer will sell
it as a lot of volvo equipment uses that grade.

(JAXAshby) wrote in message ...
With all that, I don't see any reason that a 20w-40 or 20w-50
would not be a preferable choice to plain old SAE 20, 30, or 40 which are
all recommended in my 1987 manual.

operating weigh above recommendations can harm seals. thus using 20w-40 in
place of 20w doesn't do any good for lubing upon engine startup and can do some
harm when the engine is warm.

some people are under the mistaken impression that multi grade oils "thicken
up" as they warm up. they don't. they just thin out less as they warm up.

here is an explanation as to why not to use a multigrade oil unless
specified by the manufacturer
hope this helps

Here's some info on mulitgrade Oil -- My father in law owned a Lincoln
mercury dealership for over 30 yrs. When I first started working for
him, part time. I watched as 30 new Lincolns came to the car lot via
tractor/trailer and getting unloaded. My father in law, stated. Joe,
drop the oil on each car, and fill with 20/50 oil (this was in the yr 1974)
I asked why ? is not the oil from the ford factory any good ??? he stated
yes the oil in them is good, (first reason) but if you want a quiet
Lincoln, you run 20/50 oil, (the second reason) my father in law, also
stated, from repairing engines, 20/50 in most climates will make the engine
run smoother, longer service, and less repair,other than (extremes like
Alaska) or South America

Now we notice, 30 years later (2004) most oil companies list 20/50 for
racing and extreame usage of a engine. I guess this info would also apply
to inboards

billie, you were told to stay out of any and all discussions re oil until you
bring yourself up to speed, and that will be at least a year of seriously hard
work for you.


Date: 9/20/2004 1:32 AM Eastern Daylight Time
Message-id: et

Well jaxass, how come cars have successfully run for years with straight
weight? My Ford 351W in the boat calls for straight 30 weight. You again
show you are even dumber than asslicker and that is hard to accomplish.

"JAXAshby" wrote in message
...
bill, knock it off. straight weight oil takes many, many, many seconds
longer
to flow to all pressure oil bearings in a just started, ambient temp
engine
than does multi-weight oil.

straight weight oils are proper only for engines that are started with
proper
care to prelube and brought up to temperature before putting a load on it
and
are run for extended periods of time before shutdown.

bill, you don't have a clew what the paragraphs above mean, so just knock
it
off and don't post again on oils.

"Calif Bill"
Date: 9/18/2004 10:04 PM Eastern Daylight Time
Message-id: . net

You do not have the huge temperature differentials that cars have. Most
of
the time you are in the 40-75 degree ambient temperature range.
Bill

"Dan Olstad" wrote in message
link.net...
As the season draws to a close I am thinking about fluid changes in my
new
to me boat. I have 1987 Mercruiser 260s and the manual recommends
straight
30W oil. Why not a 20-40W or a 20-50W? The manual says that's ok if
straight weight is not available but it is not recommended. Can anyone
shed
any light on this for me? Thanks.-DanO

GM has been recommending 5w-30 since the mid 80's, and 10w-30 since the 70's.


Here's some info on mulitgrade Oil -- My father in law owned a Lincoln
mercury dealership for over 30 yrs. When I first started working for
him, part time. I watched as 30 new Lincolns came to the car lot via
tractor/trailer and getting unloaded. My father in law, stated. Joe,
drop the oil on each car, and fill with 20/50 oil (this was in the yr 1974)
I asked why ? is not the oil from the ford factory any good ??? he stated
yes the oil in them is good, (first reason) but if you want a quiet
Lincoln, you run 20/50 oil, (the second reason) my father in law, also
stated, from repairing engines, 20/50 in most climates will make the engine
run smoother, longer service, and less repair,other than (extremes like
Alaska) or South America

Now we notice, 30 years later (2004) most oil companies list 20/50 for
racing and extreame usage of a engine. I guess this info would also apply
to inboards

ben, that is utter bull****.

a 30w oil will keep its viscosity over a much broader temp range then
a multi weight oil.

30w oil viscosity ***changes*** over the entire temp range.

ben, that is utter bull****.

just to clarify jax a 5w-40 oil is 40 at rest/cold therefore will take
more time to pump anywhere being theoretically 25% thicker then a 30w
oil.

5w-40 is ***5w*** at cold temp.

kriste on a crutch, ben, 14 year old boys know this.

bennie, I own a mid-80's Fiero and right on the oil fill cap if embossed the
directions to use 5w-30 oil. That means for 20 years at least the manufacturer
GM has recommended multi-weight oil.

in fact, GM has recommended multi longer than that, since the 1970's

go ahead. tell us it was a GM plot to sell us more cars.

manufacturers dont make recommendations for no reason, follow them and
you will never have any trouble.
if you are having trouble finding a 30w oil any volvo dealer will sell
it as a lot of volvo equipment uses that grade.

JAXAshby wrote:
bennie, I own a mid-80's Fiero and right on the oil fill cap if embossed the
directions to use 5w-30 oil. That means for 20 years at least the manufacturer
GM has recommended multi-weight oil.

in fact, GM has recommended multi longer than that, since the 1970's

go ahead. tell us it was a GM plot to sell us more cars.

Larry doesn't post here anymore.


--
We today have a president of the United States who looks like he is the
son of Howdy Doody or Alfred E. Newman, who isn't smarter than either of
them, who is arrogant about his ignorance, who is reckless and
incompetent, and whose backers are turning the United States into a pariah.

What, me worry?

bennie, knock it off. take your paranoia and head to the mountains with your
wife and kid and 150 sacks of rice.

(BenC)
Date: 9/20/2004 2:33 AM Eastern Daylight Time
Message-id:

(JAXAshby) wrote in message
...
With all that, I don't see any reason that a 20w-40 or 20w-50
would not be a preferable choice to plain old SAE 20, 30, or 40 which are
all recommended in my 1987 manual.

operating weigh above recommendations can harm seals. thus using 20w-40 in
place of 20w doesn't do any good for lubing upon engine startup and can do
some
harm when the engine is warm.

some people are under the mistaken impression that multi grade oils
"thicken
up" as they warm up. they don't. they just thin out less as they warm up.

here is an explanation as to why not to use a multigrade oil unless
specified by the manufacturer
hope this helps