If you live in Florida then you really don't need to worry about multigrade
oils. Run 40 weight and you are fine. If you live in Bismark North Dakota
in the winter time a multigrade oil is exactly what you need.

Rod, engine manufacturers recommend multi-grade oils for Florida as well.
engines still need pressure oil upon startup, even at 22C


Rod McInnis

guys, ask the manufacturer of the engine for the kriste's sakes, and every last
one of them flatly states multi-grade for most all but extremely unusual,
virtually unheard of conditions for a recreational engine.

btw, Mercruiser isn't a manufacturer of engines. but play silly pattycake with
each other for as long as you wish.

From: WaIIy
Date: 10/7/2004 12:12 PM Eastern Daylight Time
Message-id:

On Thu, 07 Oct 2004 09:12:24 -0400, JohnH
wrote:

On Thu, 07 Oct 2004 11:59:35 GMT, "Billgran"
wrote:

rmcinnis wrote:

Another important aspect of the rating is the fact that SAE motor oil is
rated at 100 degrees C. When you need the viscosity this is the
temperature that you oil is likely to be at.


"K. Smith" wrote in message

Yes & there is the rub with raw water cooled boat motors.



One thing to keep in mind is that inboard and stern drive engines run with
hotter oil temperatures than their automotive cousins, even though their
coolant temperatures are around 140-165 vs. 180-210. An automotive engine
normally operates at a much lower power output and rpm (2500 rpm @ 70mph)
and air flow is constantly flowing over and around the motor while running
down the road. That air from the car's volocity and/or the radiator fan
absorbs the operating heat emitted from the engine and the oil pan.

In a boat, an engine is located in a cramped area and also is sometimes
insulated to reduce sound and heat transfer to the other areas of the boat.

There is no 70mph air flow helping to cool the motor or the oil pan. A
marine engine is cruising at a much higher rpm and power output for hours
at
a time. The internal parts of the engine, pistons, rods, bearings, etc. run

at a much higher temperature than the 140 degree cooling water, and the oil

has to asborb that extra heat. The combination of limited air flow and
higher power output in a confined space make the oil in a marine engine run

quite a bit hotter than in cars. You can test this out by using an infrared

temp gun on your boat and your car if they use similar engines. It is
especially true if you run the car and the boat at the same speeds for
several hours.

In a previous post, Karen was correct in a way. When a multi grade oil gets

severely overheated, the oil can thicken up depending on its additive
components. Today's mulit grade oils are much more heat tolerant than the
ones from years ago.

Bill Grannis
service manager




OK, Bill. Thanks for the info. Now, what should I put in my 1997, 5.7L
Mercruiser I/O, given that my boating is done in the Chesapeake Bay.

John H

That was also my question. What oil for 1989 5.7 in Cleveland?

Also, must the oil be Mercruiser brand? Is there a basic difference between
'marine' and other oils?

John H

yer kidding, right?

kriste on a crutch! no wonder powerboaters stop running their boats by
mid-July. Not only are they broke from fill the fuel tank, but their engines
are worn to shreds by listening to each other.

hey, whoring, it was you who asked to really stupid question, not hoary.

next, you are going to ask if the gas used to cook pancakes at the local IHOP
is different from the gas used to cook pancakes at the house down the street.
(you, of course, being from a lesser class have a electric stove to cook
pancakes to with your Tang.)

Also, must the oil be Mercruiser brand? Is there a basic difference between
'marine' and other oils?

John H

yer kidding, right?

kriste on a crutch! no wonder powerboaters stop running their boats by
mid-July. Not only are they broke from fill the fuel tank, but their
engines
are worn to shreds by listening to each other.


STFU jax, and go argue with Harry.

John H

On the 'PocoLoco' out of Deale, MD,
on the beautiful Chesapeake Bay!

There are 10 kinds of people in the world,
those who do binary and those who don't!

Marine Oil is boutique oil and ---------------------------- can
----------------------------------- have an additive package tailored
to the marine environment

why on Earth would anyone believe that? The world
-------------------------------- can ----------------------- turn in figures
eights, but does it?

junnie, you are babbling. wanna know what the men/women who build extreme
performance race engines use? It goes $10 to $15 a quart, and they are happy
to pay the price.

the word ------------ can --------------------- has no meaning in this
discussion. Probably the easiest way to determine the validity of any claim
that one oil is better suited for the marine environment than another is to ask
yourself if the major oil companies make different oils for the marine market
than they make for the markets using the same base engines. If there is a need
in marine engines that doesn't exist in the same engines used in the non-marine
market those guys know it and are more than happy to make a special oil and
sell it at a special price for a special profit. If large oil companies think
is is the same, you can bet one is the same.

this ain't rocket science. oil company engineers aren't stupid.

Gene Kearns
Date: 10/9/2004 2:32 PM Eastern Daylight Time
Message-id:

On 09 Oct 2004 03:07:23 GMT, (JAXAshby) wrote:

Marine Oil is boutique oil and ---------------------------- can
----------------------------------- have an additive package tailored
to the marine environment

why on Earth would anyone believe that? The world
-------------------------------- can ----------------------- turn in
figures
eights, but does it?

If an outside force acted upon the earth in a prescribed manner, the
earth *would* turn in figure eights. Given that there are many
different bottlers of oil (as opposed to one earth), do you feel that
it is equally impossible that oils contain different additives? That's
a stretch, even for you.

Any bottler of XYZ oil (marine, or not) has the option of putting any
sort of additives into the oil they deem fit. Since there are numerous
re-packagers of oil (as well as oil producing concerns), it would be
impossible to give *one* answer to this general question.

There certainly are additives that could enhance the performance of
oil destined for high operating RPM, high ambient humidity, relatively
low operating temperatures... things that automotive oils may well
perform, but haven't been tailored to excel.

Do you have any DATA to refute this?

--



Grady-White Gulfstream, out of Southport, NC.

http://myworkshop.idleplay.net/cavern/ Homepage
http://www.southharbourvillageinn.com/directions.asp Where Southport,NC
is located.
http://www.thebayguide.com/rec.boats Rec.boats
at Lee Yeaton's Bayguide

junnie, why is it you think "viscosity" is in any particular way different from
"pumpability"?

Gene Kearns
Date: 10/9/2004 5:38 PM Eastern Daylight Time
Message-id:

On Sat, 09 Oct 2004 20:14:39 GMT, Short Wave Sportfishing
wrote:

On Sat, 09 Oct 2004 20:06:26 GMT, "DanO" wrote:


"Short Wave Sportfishing" wrote in
message
...

we recommend the use of Mercury Precision 4-Cycle 25W-40
Marine Engine Oil. This oil is a special blend of 25-weight and
40-weight oils for marine .

What crap! If you blend 25 and 40 weight oil you don't get 25w-40 you get
an average viscosity of the two oils based on their ratio. MM's 25w40 is
formulated the same way everyone else's mulit-weights are. They start with

a base 25 and add polymers (assuming that it's dino oil).


They probably start with a viscosity near 25, but the point is that
25W is a relative number used to rate the "crankability" of an engine
at low temperatures. A base stock, somewhere between SAE40 and SAE25
is employed and pour point depressants are added to make the oil shear
at lower temperatures.... thus the engine spins easier.

At 100 Deg C 5W-40, 15W-40, and SAE 40 should be in the same kinematic
viscosity range. At cold temperatures.... the lower the W number the
easier the engine will crank... single weight will (obviously) fare
the worst.

Note that the amusing point is that this specification doesn't address
pumpability.... as one poster here steadfastly believes. For
pumpability, one should reference the Borderline Pumping
Temperature... which gives the minimum temperature at which you may
expect adequate flow through your engine.

--



Grady-White Gulfstream, out of Southport, NC.

http://myworkshop.idleplay.net/cavern/ Homepage
http://www.southharbourvillageinn.com/directions.asp Where Southport,NC
is located.
http://www.thebayguide.com/rec.boats Rec.boats
at Lee Yeaton's Bayguide

junnie, after reading your meandering below, I ask again:

why is it you think "viscosity" is in any particular way different from
"pumpability"?

Gene Kearns
Date: 10/9/2004 7:16 PM Eastern Daylight Time
Message-id:

On 09 Oct 2004 22:57:58 GMT, (JAXAshby) wrote:

junnie, why is it you think "viscosity" is in any particular way different
from
"pumpability"?


You sorta missed the point, there, dood.....

Viscosity is resistance to flow and, therefore, is related to
pumpability.

The point that you have missed is that 0W is not SAE 0(it is
undefined), 5W is not SAE 5, nor is 10W equivalent to SAE 10. "W"
numbers are NOT a viscosity reference. The Cold Crank Simulator (CCS)
and Mini-Rotary Viscometer (MRV) tests are used to determine the oil's
"W" grade and are, thus, not related to viscosity.

Sorry, but 15W-50 is not 15 weight in the winter and 50 weight in the
summer.... it never had a calendar.....

--



Grady-White Gulfstream, out of Southport, NC.

http://myworkshop.idleplay.net/cavern/ Homepage
http://www.southharbourvillageinn.com/directions.asp Where Southport,NC
is located.
http://www.thebayguide.com/rec.boats Rec.boats
at Lee Yeaton's Bayguide

junnie, now listen closely. race engines are ALWAYS prelubed thoroughly before
engine startup, so therefore have no need for the rapid pumping of oil to
bearing needing pressure upon engine startup.

btw, race engine builders still use high price oil and still feel the money is
well-spent even if you still don't understand why.

junnie, why is it you -- with your decades of experience that finally qualified
you for an A&E license -- didn't know this?

junnie, you are babbling. wanna know what the men/women who build extreme
performance race engines use? It goes $10 to $15 a quart, and they are
happy
to pay the price.

Yep. and it is straight weight, too!

As you have posted no data,

junnie, I did post data. I posted that no major oil company makes a special
oil for the marine market (save 2-cycle oils, which are not part of this
discussion).