How does all of this translate to outboards that run 120f thermostats?
If the oil is formulated for 210 degree operating temps (most cars) does it
still work at 120-150?
I notice my merc 4 stroke has pretty low oil pressure 20-30 hours into an oil
change when I run Merc 10-30. If I use an auto brand it acts the same way. It
does better with merc 25-40

10w-30 at 150* will give less oil pressure than 30W at 150*

The advantage of multi oil is engine lube at ambient temp start up.

(JAXAshby) wrote in message ...
How does all of this translate to outboards that run 120f thermostats?
If the oil is formulated for 210 degree operating temps (most cars) does it
still work at 120-150?
I notice my merc 4 stroke has pretty low oil pressure 20-30 hours into an oil
change when I run Merc 10-30. If I use an auto brand it acts the same way. It
does better with merc 25-40

10w-30 at 150* will give less oil pressure than 30W at 150*

The advantage of multi oil is engine lube at ambient temp start up.









im fairly sure i can just ignore your childish posts jax as its fairly
obvious you have no clue what you are talking about.

http://www.autoeducation.com/autoshop101/oil-change.htm

read and learn. have a nice day.

I don't want to get in the "less filling" "tastes great" battle about whether
multi grade oils thicken or stay the same over the 0 - 210f range but I do know
that 10-30 starts out holding about 40 PSI right after a change in my boat and
in about 15-20 hours it is more like 35. Something is going on.
That is using Merc oil or a good auto oil. If I bump it up to 25-40 it is
better. Straight 30 acts about the same as the 25-40.
Since I am never going to be in my boat if it is much below 70 degrees (air). I
am not sure why I am not just running 30HD. Cooling water will range from 67f
to 88f (5 year min/max) based on the water samples I do for the state.

if ANYone tells you multi grade oil "thicken up" after they warm (I saw the
clown from Mack Boring, Larry Berlin make that very claim in a seminar), invite
them to put a $100 bill on the table. Then, you pour room temp 10w-40 oil into
an old frying pan on the stove. notice how it moves around when you tilt the
pan. Turn on the burner and wait a couple minutes. Then tilt the pan again
and notice how the oil moves around.

Duh. any clown who tells you multi's "thicken up" has not once in his life
pulled a dipstick on an engine with multi when at room temp and again when at
operating temp.

dumb, dumb, dumb.

I don't want to get in the "less filling" "tastes great" battle about whether
multi grade oils thicken or stay the same over the 0 - 210f range but I do
know
that 10-30 starts out holding about 40 PSI right after a change in my boat
and
in about 15-20 hours it is more like 35. Something is going on.
That is using Merc oil or a good auto oil. If I bump it up to 25-40 it is
better. Straight 30 acts about the same as the 25-40.
Since I am never going to be in my boat if it is much below 70 degrees (air).
I
am not sure why I am not just running 30HD. Cooling water will range from 67f
to 88f (5 year min/max) based on the water samples I do for the state.

I
am not sure why I am not just running 30HD.

because 30w does not lube pressure oil bearings as quickly upon engine startup
as does 5w-40. Not by a long shot. you can hear the difference, easily.

because 30w does not lube pressure oil bearings as quickly upon engine
startup
as does 5w-40. Not by a long shot. you can hear the difference, easily.

My point is Merc says to use 10w-30 OR 25W-40. (the only grades they sell)
30HD seems to be right in the middle.
Merc doesn't make 30HD and I suspect that has more to do with the recomendation
than anything.
I do know their 10W-30 is breaking down after 20 hours and I am losing oil
pressure. That is not a good thing.

Before you ask, no they don't have any answers ... I asked.

My point is Merc says to use 10w-30 OR 25W-40. (the only grades they sell)
30HD seems to be right in the middle.
Merc doesn't make 30HD and I suspect that has more to do with the
recomendation
than anything.

Merc doesn't make any oil, it merely repackages it (or more accurately, it has
it repackaged for them).

straight weight oils have not be recommended by major engine manufacturers (of
these kinds of engines) for a couple decades. multi grade oils were developed
to give better lubrication upon engine startup while still giving proper
lubrication at operating termps and loads.

Merc doesn't make any oil, it merely repackages it (or more accurately, it
has
it repackaged for them).

Exactly why I wonder if all of the "automobile" advice applies to marine
outboards. This is oil made for the auto industry where the "starting" range is
0f or below to a normal operating temp of over 210f (what most auto thermostats
run).
That is an operational range of 200 degrees or so.
Outboards seldom start below 70f and it is closer to 80 most of the time here.
The thermostat is 120f.

Greg wrote:
because 30w does not lube pressure oil bearings as quickly upon engine
startup
as does 5w-40. Not by a long shot. you can hear the difference, easily.


My point is Merc says to use 10w-30 OR 25W-40. (the only grades they sell)
30HD seems to be right in the middle.
Merc doesn't make 30HD and I suspect that has more to do with the recomendation
than anything.
I do know their 10W-30 is breaking down after 20 hours and I am losing oil
pressure. That is not a good thing.

Before you ask, no they don't have any answers ... I asked.

I still wonder if my Atomic-2 engine would work better, or longer,
if the recommended 10w oil was replaced by 10-30?

My oil pressure goes from 20# cold to 7 or 8 when warmed up to the
"warm" range. I have no thermostat, so the engine is always working
'cool.' Plugs carbon up, I don't care, they are still cheaper than
gas and easily replaced, but my valve guides, piston tops, etc, are
all black, I suspect.

All I want is to get to and from a mooring with reliable backup if
the sailing or current puts me onto the nearby rocks, and the
occasional one day voyage sometimes under power as the times
require, to and from the cottage and the ramp.

Terry K

I still wonder if my Atomic-2 engine would work better, or longer,
if the recommended 10w oil was replaced by 10-30?


10w oil was not the recommended oil, but rather 30w. and yes, it will last
longer if you use 10w-30, unless you start it and run it for hours on end on
end on end on end on end on end on end on end on end on end on end on end on
end on end on end on end on end on end on end on end on end on end on end on
end on end on end on end on end on end on end on end on end on end on end on
end on end...